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YC W13 Will Be Smaller ycombinator.com
134 points by jkopelman  2 hours ago   40 comments top 17
edw519 2 hours ago 4 replies      
Why was 66 ok and 84 not?

Maybe it had less to do with magnitude than direction.

I look forward to reading about yc start-ups, but increasingly find myself shaking my head, wondering how some of them will ever amount to sustainable businesses. I've always attributed this to the fact that yc must know a whole lot more than me.

But pg's recent disclosure that so many yc start-ups have co-founder issues really got me wondering. I find it unimaginable that any team can work itself into such a good position and then blow it away over seemingly petty issues. Is it possible that some trend other than scale is at work here?

jcdavis 2 hours ago 2 replies      
I'd be curious to know what broke. Companies in the last batch having a harder time getting funding?
msrpotus 28 minutes ago 1 reply      
I'm curious: what did you find were the predictors of failure? Was it a matter of focusing on problems (with the assumption that the teams with the least problems were, on balance at least, more likely to be successful)? Or did you find that there were certain counterintuitive factors that made a team likely to fail, even if they seemed solid?
rdl 1 hour ago 1 reply      
Potential ways to get past the 66 bottleneck:
1) Try it in the winter. I theorize (without as much data, obviously) that "summer projects" are more likely to be drama filled than something Jan-Mar.
2) Consider 2.5 or 3 classes. You'd still end up with 150+ companies per year. I know it would sort of screw with the current schedule, but there could be some overlap, although at the cost of partner happiness. Maybe have the .5 session be split over a longer period of time, with interviews happening slightly offset from S and demo day slightly offset from W. The longer period would be useful for certain kinds of startups.
3) Invest in a human cloning startup. Once there are 80 clones of each partner, scaling becomes easier. This may take tens or hundreds of years to be effective.
Uhhrrr 1 hour ago 1 reply      
Might this have something to do with Dunbar's Number of ~150?


rdl 1 hour ago 0 replies      
I wish there were a way you could publish the predictors of failure in a way which wouldn't let people "game" the system unreasonably.

Actually, I think you have always published many of the predictors of failure. http://www.paulgraham.com/startupmistakes.html seems like a good start, but there are probably more specific indicators during an interview or during 3 months before Demo Day.

The ones which seem most relevant are all variants "not making something people want" -- either not making something effectively at all, or that which you make is a bad idea/market, or making something which is a good idea but crap implementation. Obviously several potential causes of each.

kellysutton 49 minutes ago 0 replies      
I think the math behind YC and incubators can sometimes falsely justify an increase in the quantity of companies accepted.

If you look at each class and say, "Well, last year we had 5 breakouts out of 50. Why not increase that denominator to change the numerator?"

Unfortunately when you do this too quickly, the numerator doesn't change. It stays the same or sometimes even decreases (in my example, holds at 5).

Staying focused while growing is a very difficult thing to do.

tlrobinson 2 hours ago 3 replies      
I'm curious how you fix the post-lunch bias without overcompensating? Eat small snacks throughout the day instead of lunch?
peterjancelis 45 minutes ago 1 reply      
Dunbar's number is the amount of social relationships an average human can have: 150.

Maybe at 84 startups the total number of founders went above 150?

tptacek 1 hour ago 0 replies      
50 is still a huge number. Airbnb's class, just 4 years back, was only 16.
ig1 1 hour ago 0 replies      
What were the predictors of failure ?
talkingquickly 2 hours ago 0 replies      
It would be very interesting to hear more about what the key predictors of failure you looked for were?
hiddenstage 1 hour ago 0 replies      
Did YC bring in less interviewees this batch than summer 2012?
blueprint 1 hour ago 1 reply      
What does it mean that the interview process is "decentralized"? Seems pretty centralized to me: only YC partners or friends of partners do the interviews, and they even require traveling to Mountain View in general
senthilnayagam 47 minutes ago 0 replies      
YC has gone mainstream , highly competitive, but so are the egos of the cofounders, not everybody is willing to work straight for 12-24 months for a potential exit on the same idea
deepkut 1 hour ago 0 replies      
It's interesting that Josh Kopelman submitted this.
namank 1 hour ago 0 replies      
Give yourselves more time by adding a month to each session. Reduce the number of sessions per year and increase the duration of each.
You don't have to be local sivers.org
105 points by joeyespo  3 hours ago   19 comments top 8
edw519 2 hours ago 0 replies      
I prefer to be global with peers and local with customers.

In person, I rarely meet like minded souls with whom I can have intimate technical discussions, but on-line it's easy (thank you Hacker News friends).

But with customers, I've never found a good substitute for being there with them. I want to see everything they're doing, listen to them bitch, and feel their pain. I want to suffer with them during the day and celebrate with them over beers at night. You just can't do that the same way on-line.

patio11 2 hours ago 0 replies      
The words "pick your brain" are virtually never good ones to lead with, by the way, because they turn off many people who have useful things to say, in addition to dsivers. (Close second: "Can you mentor me?") They suggest the interpersonal equivalent of the planning meeting from heck, with no agenda, no goals, and no way to safely declare failure and thereby avoid the next meeting. If you want a specific thing, asking for it is better. If you do not know what you want, a) strongly consider whether that problem will be alleviated with another person using cycles on it or not and/or b) figure out what you want, and how helping you get it helps them, prior to asking for anything.
sivers 2 hours ago 1 reply      
P.S. to my Hacker News peers : This is a one reason why I decided not to live in the SF/Bay area. So many people so like me that I felt pulled into all the in-person kind of stuff. I feel more productive & more balanced when living in a more remote place.
graue 19 minutes ago 0 replies      
I can't imagine living in a place for three years and not making any friends.

For me, regular in-person contact with friends is essential to feeling motivated and connected with the world. They don't have to be close friends, and they don't need to share my career or understand the work I do as a web developer. Most of the programmer friends I would sling code with on a weekend project are global â€" scattered across the world. Whereas, many of the friends I hang out with the most locally use feature phones, have old or no computers, and think Twitter is pointless.

But that doesn't matter because what I need them for is to sit down and have a good conversation. Or play a game of table tennis. Or ride our bikes out to the suburbs and back. If I don't get these kinds of outlets, a week spent sitting down and coding leaves me feeling strangely unphysical, unhinged from the world around me.

I've grappled with the local/global issue because my life does feel like a duality, where local (mostly offline) and global (online) are separate. I'm not sure how to resolve that (maybe living somewhere with more early adopters of tech would help). But Derek's solution is an extreme one. You don't have to be exclusively local or global.

tumult 2 hours ago 1 reply      
Nice article.

Coincidental timing for me. I'm Singapore for a few weeks, and even though I've spent months here in the past and have a long-term visa, I have almost no local friends here. I feel like I should feel guilty about it. But I don't feel guilty about it, except in an abstract way.

I spend most of my time coding and working on music. And eating Thai food.

stickhandle 2 hours ago 2 replies      
I don't know the author, but my initial take is: loner, work-a-holic, egotist. None of that is meant as an insult. To "socialize" in a local sense doesn't need to mean you meet "with over 400 people, one-on-one, went to every conference and get-together, and said yes to every request". It means making friends: the kind that build decks together (with free beer); go bowling, watch the big game together at the pub instead of at home, go for a hike with the kids, meet up at the coffee shop every Thursday morning, and simply help and grow together. Its not work. Its natural. Fun. Community. The author is missing out.
guylhem 2 hours ago 1 reply      
There are many great insights, but I wonder how appliable they are in the real life.

I mean, I especially loved the answer based on the idea of "not favoring anyone", when the author was asked about what he did for the local market.

But this requires some "enlightenment" - as the author said, he lived in many places, so he can now relate to human being as equals - wherever they come from or live.

It seems to me it is just wishful thinking to believe most people - or just a significant enough mass - will be able to think like this.

Most people are lost in their own thoughts and community. They just can't think global, and certainly don't want to.

They just care about the ones they know - and cronyism is just an artifact. It's the same story again an again - dozens of people dying is the news, but having a deep cut in your little finger is a tragedy.

fwr 2 hours ago 2 replies      
Let's eliminate any social interactions to pursue maximum effectiveness, then we can finally focus on the things that matter - like programming! Beep, boop.
Improving Your Python Productivity github.com
68 points by ozkatz  2 hours ago   11 comments top 4
kbd 2 hours ago 3 replies      
Not a very helpful article. Far from a general "improve your Python productivty", it's more like "here are some minor random Python features that I think are useful".


* Use dict and set comprehensions.

* Use collections.Counter.

* Use json.dumps or the pprint module for pretty printing.

* Create simple web services with Python's XML-RPC library.

* Use open source libraries...

buster 8 minutes ago 0 replies      
Despite the negative comments here, it's always good to be reminded of some of nice built-in things.
Reminds me how awesome pythons standard functionality really is.
eddyweb 1 hour ago 0 replies      
As someone just said on reddt #4 reminds me of python -m SimpleHTTPServer. Very useful, even when you are not coding in Python!
Zoophy 1 hour ago 3 replies      
Whitespace as syntax? Really?
Understanding The Fourier Transform altdevblogaday.com
29 points by mannjani  1 hour ago   5 comments top 4
dropdownmenu 23 minutes ago 1 reply      
You can also think of the Fourier Transform as a projection (dot product) of a signal onto the space of all sinusoids. That's the explanation that made everything click for me.
ColinWright 1 hour ago 0 replies      
You might be interested in the discussion from one of the previous submissions of this:


Here are some other items about the Fourier transform:


frozenport 18 minutes ago 0 replies      
I would like to see more of these articles cover the phase portion.
bmease 13 minutes ago 0 replies      
I really liked where he color coded the equation and the sentence describing how it worked. I've seen tables in the past explaining what each variable represented, but this was much clearer.


Never mind talent: Practice, practice, practice philly.com
48 points by tokenadult  2 hours ago   24 comments top 6
unoti 1 hour ago 2 replies      
I've long felt that my intelligence is only average, and I've always tried to compensate by working hard. It had been 20 years since my last calculus class when I returned to college, and I was quite worried I'd not be able to keep up. I worked my way through most of a small calculus book before starting the class, to refresh what I'd forgotten. During the class, I spent something like 5-6 hours per day during the week working on Calculus, and around 10 hours per day on the weekends. I worked and reworked every problem until I fully understood what was going on, comparing my answers to the answer key for the odd problems, and computer algebra systems for the even ones when possible. I worked so hard it would have been embarrassing to admit it to my classmates. Only a retard would have to work so much, I thought, but I was determined to be the best I could. I ended up at the top of the class.

The point is, if you're really determined, working hard can go a long way. The key is to try not to worry about the other people that make it look easy. Later I heard this quote:

"If people knew how hard I had to work to gain my mastery, it would not seem so wonderful at all." - Michaelangelo

sown 1 hour ago 5 replies      
So what about when you have someone like me who works hard and still fails? I vary my methods. change my environment to make it easier, pay for training, do what ever. I examine what I did wrong, I still get it wrong, no matter what.

Let me share with you an anecdote: In undergrad, I took an intro computer networking class. Everyone else could understand what was going on. There was no assigned reading material and lectures didn't follow from any text. I always was the lowest student in the class, no matter how hard I tried. Everyone else could understand it quickly. I worked hard on that class but it didn't matter. Not everyone who works hard will show positive results, I guess. I more or less flunked my way through school. Sometimes I'd work hard, sometimes not. It didn't seem to matter.

Or, if I'm facing someone who has worked hard and is also very intelligent? I don't have a chance.

The rhetoric of these articles and the rest of these posts here have a coded meaning behind them: there are no disadvantaged people or students -- only stupid or lazy ones. It's a corollary of Survivor Bias. If you work hard, everything will be peachy-keen OK and nothing will go wrong. If you work hard and fail, you deserve only scorn.

For me, it was, never mind if you work so hard that ignored everything else, worked so hard to not get beaten by your parents, worked so hard to get mastery of material -- I must be still too lazy or stupid since I failed.

I don't know what it is that I don't have that everyone else does. I'm likely to not ever know.

This is a topic that I'm very familiar with so that's why I wrote a lot about it and sound perhaps a little crazy.

mershad 9 minutes ago 0 replies      
Interesting to consider, though not discussed much in the article: quality of practice is paramount. Thoughtful and deliberate generates incremental progress. Casual, mentally checked-out practice isn't practice at all. Some discussion & sources here: http://ideas.time.com/2012/01/25/the-myth-of-practice-makes-...

One mantra tossed around of late is "_perfect_ practice makes perfect," meaning not to never make mistakes, but to be conscious and analytical when you do.

kiba 2 hours ago 1 reply      
Genius is not a thing, but a process. Genius need the proper environment to cultivate talents like our well endowed genetically engineered corns need fertilizers and pesticides.

It doesn't matters if you have an IQ of 200 when you're born several thousand years too early. You never make use of your genius, except to make lot of babies and become the chief of your tribe, if you're lucky.

Granted, there's lot of people who are innately smarter than you, but chance are they're also stuck in various positions of life where they can't become a genius like a job at wal-mart, or having children too early, or is stuck in a hut in a third world country somewhere.

If you're reading this, chance are you have the money and the time to rearrange your environment and your behaviors to achieve mastery. The hard part is figuring out how to do that and how to sustain that.

_nato_ 1 hour ago 0 replies      
I studied violin at Juilliard with the great Dorothy DeLay. She taught the greats such as Perlman and Midori, and she insisted that 'talent' was nothing more than a 'mood.' I will always treat her viewpoint on this as gold having taught so many youngsters over the decades. So, work hard, and think big of yourselves as your reward (although that can be so hard to do!)
tchock23 1 hour ago 0 replies      
If anyone is curious as to the research on this topic, check out Carol Dweck's book "Mindset." It has a ton of examples from academia, sports and business on fixed vs. growth mentalities and how that plays into a person's success in life.
Is zero an even number? bbc.co.uk
17 points by ColinWright  1 hour ago   22 comments top 7
huhtenberg 45 minutes ago 4 replies      
> The use of the phrase "even number, or the number zero" implies that zero is not even.

Ah, no. It implies that some gas station attendants might think that it's not. It's idiot-proofing the instructions.

agentq 3 minutes ago 0 replies      
I tried to convince the croupier that zero was an even number, but alas ...
joejohnson 15 minutes ago 1 reply      
Yes, it is. Please don't upvote fluff pieces like this.
zem 16 minutes ago 0 replies      
key sentence:

> According to Dr James Grime of the Millennium Maths Project at Cambridge University, reaction time experiments in the 1990s revealed people are 10% slower at deciding whether zero is odd or even than other numbers.

jonsen 9 minutes ago 1 reply      
Is zero even a number?
bcuccioli 19 minutes ago 2 replies      
The irony of this article is that the author is trying to sneer at someone for making a mathematical mistake, which is not technically wrong, but himself falsely asserts that "The use of the phrase 'even number, or the number zero' implies that zero is not even", which is not true in the usual first order logic.
Leszek 34 minutes ago 1 reply      
Slow news day over at the bbc?
Books of a Highly Effective Programmer (2009) fogus.me
96 points by krat0sprakhar  5 hours ago   19 comments top 7
meaty 2 hours ago 3 replies      
I think this should be:

7 books of a highly academic programmer.

A highly effective programmer probably should be reading other topics as to be honest, most of programming is laborious non comp Sci stuff.

tinco 3 hours ago 2 replies      
Hi, could anyone help me with understanding why the lambda papers deserve a whole book? What I understand from the history is that they are a set of papers that define and explain the Scheme programming language.

If so, shouldn't the book be broader by including more of literature on LISP or even AI programming in general?

phillmv 3 hours ago 2 replies      
1. Couldn't he have linked to some of this stuff?

2. Some of this stuff is absurdly broad and weirdly pandering.

3. "I have no idea what the copyright implications of this are, so I will be printing out only my own private copy and not making them available publically;" is a totally inadmissible position for a professional programmer to have. The answer is, no, of course you can't make a printed compilation of other people's work and put it up for sale.

econner 3 hours ago 0 replies      
If the first link under Core to the 10 papers is not up for you:
keefe 2 hours ago 1 reply      
If I'm going to diverge from read code, write code long enough to do this much reading... I'd rather start with the papers and books recommended for the phd qualifying exam at the top 10 universities.
darkxanthos 2 hours ago 0 replies      
And they're all comp sci books. Someone has a very narrow view of what it means to be a programmer.
Icons for Web and Other Businesses davidmatthias.typepad.com
23 points by dmkov  1 hour ago   3 comments top 3
bitcartel 7 minutes ago 0 replies      
The download is one big TIFF. Is there a tool or script to cut out each icon as an individual image?
bpatrianakos 39 minutes ago 0 replies      
No matter how many free icons get released I always love 'em. You can never have too many icons even if they're the same but just marginally different.
nateweiss 1 hour ago 0 replies      
These are nice, and appreciated. Bought the colored ones as a small bit of support. Hope to see more in the future.
Photobooth.js - A HTML5 Webcam plugin for jQuery wolframhempel.com
14 points by wolframhempel  1 hour ago   4 comments top 4
phpnode 17 minutes ago 0 replies      
I'm currently finishing off a project that would have seriously benefited from html5 webcam support. The current state of things is really frustrating, in the latest chrome and firefox you can access a webcam and take pictures, but it's not possible to actually do anything with the video stream, you can't broadcast it to the server without horrible (and slow) hacks, so it's really crippled. That's the frustrating thing about html5 generally at the moment, it's eventually going to be awesome, but you can't actually use a lot of it yet.
bpatrianakos 43 minutes ago 0 replies      
This is awesome! Thank you for making and sharing this! I recently launched a web app and of course users can upload profile pictures. I totally plan to implement this and allow users to take pictures from right within the app! Feel free to check it out and see your excellent work in action - https://writeapp.me it's free).

A few minor problems, though - it kind of slows the down the browser. Like a lot. I'm using a new Macbook Air and this thing is incredibly fast and has actually never slowed down on me once (and I really abuse it). Also, it seems like the image is kind of stretched. Maybe I'm getting fat and don't realize it. But all in all, excellent work. Would you consider putting it on GitHub and allowing people to contribute? I'd be first in line!

wolframhempel 28 minutes ago 0 replies      
Thanks :-). It's doing some quite heavy lifting for the HSB calculations. Every frame of the video is drawn onto a hidden canvas. The pixel data from that canvas is then read, manipulated and drawn onto the visible canvas. In Chrome and Opera this partially happens on the GPU which makes it quite smooth, but in Firefox it is slow to an extend that made me add the "videoOnly" mode. (In this mode it just shows the video element and only allows for cropping.

Would it be helpful if forcing the “video only mod”e would be exposed as a public method? (Currently it can only by switched off by setting the forceHSB flag to true.)

Please find the github repo for the project at https://github.com/WolframHempel/photobooth-js

ForFreedom 31 minutes ago 0 replies      
Some years back, it would have been great. But today we could just take a pic and upload via the mobile.
How the embeddability of Lua impacted its design acm.org
14 points by Rickasaurus  1 hour ago   discuss
In Defense of COS, or Why I Love JSON and Hate XML jimpravetz.com
8 points by hoov  56 minutes ago   2 comments top
jimfuller 22 minutes ago 1 reply      
XML, being in the markup family tree, has a lot more history then simple json encoding ... measuring its usefulness on a corner case has always been well ... boring. I am glad people are using JSON to sling simple data across the web versus markup.

Come back to me when you are using json to encode an entire document ... you might look at XML a bit differently.

tl;dr use the right tool for the right job.

E-Ink Case Turns the Back of Your Phone Into a Second Screen wired.com
18 points by rkudeshi  2 hours ago   4 comments top
cwe 43 minutes ago 1 reply      
Link to actual project on indiegogo:


Scala 2.9 vs 2.10 Performance markehammons.wordpress.com
48 points by bertzzie  5 hours ago   10 comments top 3
tikhonj 2 hours ago 0 replies      
This isn't the most compelling of benchmarks. It's still infinitely better than what most people do--the author actually measured something in a reasonable way!--but I don't think it's enough to make any interesting conclusions. I suppose it shows that there is a performance boost, which is great, but I'd really like to know where the gains really are.

Could somebody familiar with the changes to 2.10 explain where the performance boost came from and what code it will affect? Does this make Scala a more compelling choice for the discerning functional programmer?

jaytaylor 2 hours ago 1 reply      
Performance improvements are nice and all, but I'm already generally satisfied with the performance of Scala 2.8.x and 2.9.x.

What I'd really like to see is faster compile times. I know it's a tall order given the complexity of implicits, but compared to other languages Scala compilation slowness can be a tough sell.

alexjarvis 1 hour ago 0 replies      
Nice post, I just used your benchmark to also compare running Scala in JDK 6 and 7 http://news.ycombinator.com/item?id=4862035
Facebook Hackathon Finals post-mortem dylanv.org
10 points by dylanvee  1 hour ago   3 comments top 2
ChuckMcM 2 minutes ago 0 replies      
I think that Music app is awesome.
Xcelerate 52 minutes ago 1 reply      
Wow, this gets bigger every year. My team made it to the finals last year but there weren't any teams from Brazil or Ukraine. Paul seems to be doing a good job finding people all over the globe. I like the idea with Pond. I noticed that many ideas (even ones that didn't win) could be turned into viable businesses.

Anyone on here go both years?

Triple rainbow near Seatle: How was it formed? cliffmass.blogspot.com.ar
53 points by gus_massa  6 hours ago   8 comments top 5
cabacon 3 minutes ago 0 replies      
raimondious 54 minutes ago 0 replies      
There is a great lecture on the physics of rainbows on MIT's Open Courseware: http://ocw.mit.edu/courses/physics/8-03-physics-iii-vibratio...
cek 2 hours ago 0 replies      
Cliff Mass is awesome. I've become a total weather-nerd because of his writing.
ccozan 2 hours ago 1 reply      
For the first time I understood the physics of rainbows!

On the other side now it looks a little less magic...

rockyleal 4 hours ago 1 reply      
and, what does it mean?
Bitcoin Adoption Right on Schedule cs702.wordpress.com
11 points by cs702  2 hours ago   4 comments top 4
taligent 1 minute ago 0 replies      
Supporters of Bitcoin really are their own worst enemy.

You only have to look at the comments to see why most normal people aren't going to touch it with a forty foot pole.

w1ntermute 25 minutes ago 0 replies      
Isn't the Iranian govt planning on cutting the country off from the worldwide internet? Wouldn't that make the use of BTC much more difficult?
tonfa 33 minutes ago 0 replies      
The original article is very fuzzy and it isn't clear at all whether bitcoins are used in Iran (it's mostly about how bitcoins could be useful).
BrianPetro 51 minutes ago 0 replies      
Does anyone have any good resources for Bitcoin in business?
A Primer on Cheap Software Defined Radios y3xz.com
46 points by yuvadam  5 hours ago   6 comments top 3
rachelbythebay 3 hours ago 0 replies      
It's too bad the author gave up on a Mac install. If all you need is the low level fundamental C++ libraries of GNU Radio, it can be done without installing dozens of support libraries. It's when you try to get all of the Python and graphic stuff happening that it gets really complicated.

A Mac Mini with one of these $20 sticks is a decent little system for working on this stuff. It has enough horsepower, is totally quiet, doesn't take up much room, and only uses about 20 watts during ordinary receiving tasks.

I took notes on how I made this work on my Mac here: http://rachelbythebay.com/w/2012/09/19/brute/

keenerd 3 hours ago 1 reply      
Feel free to ask any questions about the rtl-sdr project. I've been watching it since it started and have since gotten a handful of commits into the project.

Some key things that were not mentioned. There is the GQRX frontend and the SDR# frontend. Both are fairly straightforward to set up and use.

Also not mentioned were the hardware differences (r820t vs e4000 vs fc0013). To get decent signals you need to add a bit of filtering to the USB power supply. And of course antennas, but that topic needs an entire book.

I've been working on a very simple sdr stack (currently merged in rtlsdr as rtl_fm) that is meant to provide a sox-like experience. It is also stupidly fast, enough so that even a little RaspberryPi can easily do pager decoding or police scanning.

rwmj 3 hours ago 1 reply      
The $15 USB dongle (actually $20) is this one right?
Or is there a recommended hackable dongle?
Show HN: Interactive SICP xuanji.appspot.com
203 points by zodiac  13 hours ago   42 comments top 10
zodiac 13 hours ago 4 replies      
Hello everyone, OP here. This is my first Show HN post.

I guess most of you should know what SICP is. I took a class where it was used as a textbook (only the first 3 chapters, unfortunately) and loved it.

Most of the syntax-highlighted code fragments can be clicked on and edited. Either click somewhere else after that or press ctrl-enter to re-evaluate the scheme code. There are also some auto-graded exercises which involve writing code, as well as some multiple-choice questions (inspired by coursera)

So far only the first section is up. I don't think I can finish converting the whole of SICP to this format, so any help is much appreciated! I've tried to make the API as short as I can, but still able to run arbitrary code (eg for auto-graders). The main code is in isicp/coding.js and the content is stored in chapter-specific html files. All this is done via client-side javascript. I used biwascheme for the scheme interpreter and codemirror for the editor.

dschiptsov 11 hours ago 4 replies      
SICP is an advanced text, and using it to teach amateurs how to program is, probably, a mistake.

Brian Harvey have done a great job to simplify and make it more freshman-friendly. I think his CS61A is the best intro course available (but I don't think that the sentence ADT is a such great idea, and it make things little messier, not more clear).

The HtDP2 approach is also remarkable, but problem is it is part of Racket promotion (word dr.racket is used hundred times in the first chapter). The idea to make changes in a program visible, via using graphical primitive functions is brilliant, but controversial one - it is too soon (but it kicks and makes a progress visible)

I think that functions with multiple arguments, first-class "citizens" (values has a type, everything is a pointer), pairs, lists, then generic functions and environments must be taught first, and visualized interactively, similar to that python tool. Then, after, you can teach parts from HtDP and then SICP.

People who really enjoyed this initiation will go through whole books themselves.)

sudhirj 10 hours ago 0 replies      
The site doesn't seem to need a server to function - so it would be awesome if you could add a cache manifest to make it available offline:


BlackJack 5 hours ago 3 replies      
Looks awesome. I think exercise 1.2 is broken. I enter in:

(/ (+ 5 (+ 4 (- 2 (- 3 (+ 6 (/ 4 5)))))) (* 3 (* (- 6 2) (- 2 7))))

and it tells me the result is wrong, but wolfram and my own REPL confirms the result.

arikrak 2 hours ago 0 replies      
If I ever get up to Scheme, I'm adding this to my chart of interactive resources for learning programming.
firesofmay 11 hours ago 1 reply      
Good initiative. I wish it was done in clojure/clojurescript, would have been great. But still its a nice way to learn.
One suggestion. Add paredit mode to balance the parens.
Without paredit mode one has to worry about balancing the parens and its a painful experience. It's like coding in notepad.
Looks great! Looking forward to more chapters :
Surio 12 hours ago 0 replies      
"Green Bar" on the right: It is the navigation menu that comes into focus once you click on it. You can focus on the content w/o getting distracted by the ToC. :)

To OP. Don't worry. It is intuitive enough (for me at least (-; )

ghubbard 8 hours ago 0 replies      
SICP - Structure And Interpretation Of Computer Programs

Is an MIT computer science textbook.


zodiac 8 hours ago 1 reply      
Sorry for repeating myself, but I really need contributors for this - I can't finish it just working on my own on weekends.
Tyr42 13 hours ago 3 replies      
uhh, It's got some sort of green bar, but it's stuck waaay over to my right and I can't read it.
Chrome OSX
A Budding War Over Internet Economics technologyreview.com
45 points by rpm4321  6 hours ago   25 comments top 9
kator 6 hours ago 0 replies      
The crazy thing is they're debating on Sender-Pays:

FTA "The conceptâ€"known as “sender pays”â€"would radically alter today's Internet economics. Some countries say their networks are groaning under video and other content provided in large part by U.S. companies such as Facebook, Netflix, and Google. These countries suggest that fees on content providers would help defray local infrastructure costs."

This is exactly why ITU and other agencies should stay out of the way. They have no clue how the internet works. Content providers do pay Bandwidth fees at their edges. If the networks are having a hard time with this content they should have not signed deals at the edges of their networks that put them in these positions. What they really want is to dig their hands into the deeper pockets of content providers and create a sort of "Tax" to improve their "groaning" networks. What would really happen is they would get the money and continue running their inefficient networks and magically the extra money would just disappear in a flash of "operating expenses".

dmix 3 hours ago 1 reply      
THIS is why the future won't be cool. It's not that the tech won't be cool, it's the never ending attempts for totalitarian control of it.
motters 4 hours ago 1 reply      
"Sender pays" is a good way of stopping those pesky citizens from communicating and turning the interwebs into a TV-like experience.
vijayr 4 hours ago 1 reply      
It's unbelievable that they even want to debate this.
wmf 1 hour ago 1 reply      
I think the other thread has a more interesting discussion going: http://news.ycombinator.com/item?id=4859882 Edit: fixed link
JoeAltmaier 5 hours ago 3 replies      
Can we kickstart an Internet satellite project? Out of the control of any regulatory institution, we could continue 'netting unperturbed.

Of course, we'd need a cheap-transceiver-project too. Hm.

mylittlepony 5 hours ago 1 reply      
It was good while it lasted. All I need now is a new entertainment and a new career. See ya everyone, you will always be in my heart.
stock_toaster 3 hours ago 3 replies      
P5 (I think this is the right term) have veto power in the security council. I dont see this passing any time soon...


j0j0r0 4 hours ago 0 replies      
frothkit - Objective-C Web Application Framework code.google.com
33 points by eluos  4 hours ago   18 comments top 7
yoda_sl 3 hours ago 2 replies      
If I was to develop some web framework in Objective-C I will at least try to mimic the WebObjects framework which has some great concept behind it.
The main grief against WebObjects that should be avoided is that the framework layer to access the database aka EOF (Enterprise Objects Framework) was never designed to use a connection pool nor work nicely in a multi-threaded environment.

Sadly Apple stopped the development of that web solutions years ago and kept it for itself... I heard from various folks at Apple that there are still a few engineers improving it and it is being used a lot for iTunes.
WebObjects got some bad reputation from many people that have no clue on how it works and citing that WebObjects can't even support database update and this why the Apple Online Store is often offline when Apple release a new product. This is total BS of course, since take the iTunes AppStore which serve the content for all stores: music, apps, books, movies, etc... And you barely see that iTunes Store is offline.

WebObjects was a great technology but Apple decided to keep it for itself.

jrajav 3 hours ago 1 reply      
Not entirely related (though I think someone actually is working on a web framework for it): ObjFW [1][2] is an Objective-C framework and runtime that provides Cocoa-like classes and methods, but with more open-sourceness and portability. It even runs on Raspberry Pi!

[1]: https://webkeks.org/objfw/

[2]: https://github.com/Midar/objfw (Mirror)

danpalmer 3 hours ago 1 reply      
Looks like this hasn't been updated since 2010, and it's website doesn't load. Also the underlying Cocoa port looks like it hasn't been updated since 2008.

I think we need a totally new Objective-C framework for web development based on newer design patterns, GCD, etc, but it needs a new port of Foundation and Cocoa to Linux and other systems.

As much as I'd love an Objective-C web framework, I wouldn't use one that only ran on Mac OS, pretty useless in terms of production hosting I think.

scraplab 4 hours ago 0 replies      
RoutingHTTPServer[1] is nice lightweight library on top of CocoaHTTPServer[2], which behaves a little like Sinatra.

[1]: https://github.com/mattstevens/RoutingHTTPServer

[2]: https://github.com/robbiehanson/CocoaHTTPServer

ddfreyne 4 hours ago 0 replies      
Seems to be inactive. It hasn't been worked on since June 2010.
fyolnish 4 hours ago 1 reply      
Since we're doing this: http://webappkit.org
yarrel 4 hours ago 1 reply      
I've never heard of WebObjects either.
A Free Market Fix for the Copyright Racket bloomberg.com
25 points by natex  4 hours ago   13 comments top 3
loarabia 3 hours ago 2 replies      
Given other issues floating around maybe rather than go to something as restrictive as what was proposed at the end of the article take a half step.

Leave much of the law today as is (copyrights can apply to more than the original copyright law allowed and are automatically in force even without registering) but change the duration mechanism.

For the first 14 years of the work's existence you get a copyright for free.

For the next 14 years, you can re-register but with a higher but still nominal fee.

For each year after that, you must re-register and the fee goes up at an accelerating rate eventually reaching millions per year per copyrighted item. I'm assuming there would have to be a cap somewhere.

The government gets new revenue, most copyrights are shortened and enter the public domain more quickly and for the copyrights that are extremely valuable and still producing value in excess of the ever increasing registration fee, it will be worthwhile for the holder to pay.

mtgx 3 hours ago 3 replies      
If there was a time or an issue that Republicans could stand for and actually be pro-market as they keep saying they are (in theory), it's this one. They'd probably get as much support as they usually get from evangelists, which seems to be their core audience these days, or at least that's how they're acting in public.
j0j0r0 3 hours ago 2 replies      
however, a more direct example would be mickey mouse...
Exynos based quad-core developer boards, starting at $69 hardkernel.com
47 points by sharmajai  7 hours ago   38 comments top 5
drivebyacct2 4 hours ago 4 replies      
This is the SOC in the Nexus 10 right? Is someone working on a linux port for the N10?

How's the video acceleration on this? I need to start a blog. I read like 2-3 hours worth of ARM news once or twice a week trying to track down the best HW/SW/price combination for a simple dumb XBMC-upnp frontend.

The Rockchip devices have pretty crap support, though AMLogic released some sources that might help. Allwinner is finally making progress via AW's CedarX, though it's apparently still sufficiently buggy and they're back at the mercy of Allwinner.

I've yet to see much about the Samsung setup though. I love the Exynos and would very happily spend another $100 in an attempt to find the right thing.

That having been said, there are ~$50 versions of the HDMI stick that have powerful Cortex A9s in them that make these look over priced.

trotsky 5 hours ago 6 replies      
Too bad none of these various hobbyist boards come with socs that support gigabit and sata. my $400 512mb single core synology nas is very jealous.
neya 6 hours ago 3 replies      
Just curious, is this stuff open source? Meaning, I use them for commercial production and I won't be sued for just using these boards(assuming I don't infringe on anything else)? Just curious.
Luc 5 hours ago 0 replies      
It's a great way of showing off the size of the board (the VISA number has been 'shopped).
baltcode 5 hours ago 1 reply      
I see it starting at $89.
How To Hire the Right Developer for Your Tech Startup thenextweb.com
6 points by boy88  1 hour ago   discuss
Show HN: New iOS App - Watch your videos from Anywhere tonido.com
10 points by tteam  2 hours ago   15 comments top 6
micloud 4 minutes ago 0 replies      
I like the file preview UI design (http://www.tonido.com/blog/wp-content/uploads/2012/11/iOS-Si... your app. Quite unique and very useful. Hopefully other apps copies that design pattern as well.
diziet 1 hour ago 1 reply      
Hey, cool app! It's nice to solve the local storage problem like this.

I am the founder of https://appstorerankings.net , a startup focused on ASO (App Store Optimization), so I'd looked up your app's keywords -- you're using "personal,live,movie,cloud,stream,air,share,remote" . That's only 49 characters out of 100 you could be using (or you've got duplicates with the title).

You should add some new keywords to your app, here are some suggestions - "server,vlc,player,audio,airplay,wmv,mkv,avi,nmp4" in order to get more downloads (These were automatically generated based on your current keywords). A lot of your competitors use file formats as keywords, so it's probably a good idea!

ronnier 32 minutes ago 1 reply      
When searching for "tonnido" in the app store, there are three results of the same app with different titles. What's that all about?



Tonido for AppliedMicro

Tonido for Freecom

pixelcort 1 hour ago 1 reply      
I've really enjoyed using live transcoding client apps on iOS, but have always wondered if there are any web-based live transcoding solutions. The only things I found were high end broadcasting solutions that are for live stream transcoding, not for prerecorded libraries. Perhaps a better term is on-demand transcoding or just-in-time transcoding?

Wouldn't it be cool if you could load up a URL and get transcoded audio and video of your media library for whatever browser you happen to be using?

dcguy 1 hour ago 1 reply      
Does it support live transcoding of mkv video formats like Airvideo?
markshepard 2 hours ago 0 replies      
The iPad app is pretty functional. It has some rough edges to polish but not many apps I have found that seems to handle range of files as this app.
Show HN: A Url Permanence Service purl.ly
22 points by dRocking  5 hours ago   24 comments top 14
buro9 2 hours ago 0 replies      
How do you resolve offering a permanent URL for something whilst also complying with DMCA takedowns for copyright materials when the end service may have removed the content but you continue to publish it?
shardling 2 hours ago 1 reply      
Is having a Libya based domain name really the best way to ensure permanent URL structure?
antirez 3 hours ago 1 reply      
This is a good idea in theory, but not if in form of a company. This would require something like a consortium where Google, Microsoft, Twitter, Facebook, ... and a few more federates to create a service paying for the bill and with the intention to take it up for the future as long as possible.
secure 3 hours ago 0 replies      
Sounds cool, but only as long as purl.ly itself is up. We've seen what happens with single point of failure services like this when twitter's link shortener t.co was down.
oh_sigh 2 hours ago 1 reply      
Infinite loops: http://purl.ly/tinyurl.com/qui3na

purly -> tinyurl -> baconized purly

tingletech 42 minutes ago 0 replies      
If you have an interested in permanent identifiers, you might also be interested the archival resource key standard https://wiki.ucop.edu/display/Curation/ARK and the EZID service http://n2t.net/ezid/ . Disclaimer, I work at the same digital library where the standard and the service are developed and maintained.
wut42 2 hours ago 0 replies      
benologist 2 hours ago 0 replies      
I don't like the redirect page, it's a large and heavy page with a forced delay and what looks like placeholders for a ton of ads.

It might be better packaged as something blogs and forums can automagically implement for a fee instead of trying to make money off ads.

detectify 4 hours ago 0 replies      
Tried the service and got two errors first,

I cannot add a URL that does not have "http"
I cannot type a URL that has "https"

Would be nice to be able to add https adresses and add them in any form.

Also an idea, make it as a web browser plugin so I can change the url in the brower and add it to my link library. Then it's even better. I don't like detours.

Question, what happen if I prul.ly a Url once then the content changes and I want to save the new content as well (Different content, same url)?

Anyway, I really like the concept, keep going!

Annelie @detectify

TazeTSchnitzel 3 hours ago 1 reply      
Looks like not many people are actually using it:


Foomandoonian 4 hours ago 1 reply      
Interesting choice to use a Libyan domain for a service like this.
Hello71 3 hours ago 0 replies      
So it's basically WebCite.
level09 3 hours ago 0 replies      
looks similar to what archive.org is doing, except that the later saves complete websites recursively ..
dRocking 4 hours ago 0 replies      
It's pretty quick and dirty... purl.ly links will detect a 404 at the destination and redirect you to the google cache instead. Works great if that page is in the google cache, but it may not be.

I'll get around to caching the full content of the destinations at time of purl.ly creation next, and serve that if google is missing it.

A practical guide to selling ebooks online papathanasiou.org
6 points by dpapathanasiou  2 hours ago   discuss
HTML5 Datalist davidwalsh.name
31 points by stevewillensky  7 hours ago   9 comments top 6
pav3l 5 hours ago 0 replies      

Unfortunately still not supported on safari or IE9. Don't rush to throw away those Javascript widgets quite yet.

sergiotapia 5 hours ago 0 replies      
This... this is phenomenal. Thank you for sharing this link.

This will cut my development time drastically because I use autocomplete on many different pages of an internal web application and I decide what browsers the sales people (85% of the company) use.

I'll for sure install Chrome for them and save the company time and money by using this HTML5 feature. Nice find!

pessimism 5 hours ago 1 reply      
This is truly great, and might actually be something I could useâ€"although it needs to interface with a list of hundreds or thousands of entries. I don't know if it is scalable in that case. Probably not, if it needs to display the entire list, which means that this intended for a relatively small list.

I recently had the non-existent pleasureâ€"on the same projectâ€"of implementing a fall-back for the `datetime-local` input type, which is only available on very few browsers, even though it is absolutely critical to a good mobile experience.

This fails very gracefully compared to the `datetime-local` input type turning into a `text` input.

This is one of the perks of using Opera as my default desktop browser, by the way. Shame so many developers choose to ban it.

bookcasey 3 hours ago 0 replies      
Chris Coyier made a great polyfill for datalist: https://github.com/CSS-Tricks/Relevant-Dropdowns
chris_wot 6 hours ago 1 reply      
Demo didn't work for me on iOS 6...
shannonbailey78 4 hours ago 0 replies      
Awesome feature, this will autocomplete very easy to implement.
Documentation is King kennethreitz.org
65 points by kenneth_reitz  10 hours ago   15 comments top 8
3amOpsGuy 5 hours ago 0 replies      
I've been doing some experiments to improve recall of documentation.

So far i've learned a few seemingly effective techniques:

1) Occasionally construct some weird sentences, throw grammar out the window for a sentence (any longer doesn't work) and people will recall that whole section of the document, months, even years later. I have no idea why this is so effective, but i'd love to know.

2) State an assumption and have it missing the obvious consideration. Don't make it some intricate detail, it has to be in plain sight even for someone not familiar with the topic. Again, people recall these sections and are happy to suggest how you could improve the document.

3) Never tell anyone you're playing tricks like this, it completely loses its effectiveness when people know what you're doing with the slightly strange documents.

4) Test the recall of others frequently on your text. Probe them and figure out what's easy to remember and what's not. You can use this to tweak your documents for future.

5) Don't over use it. The goal doesn't have to be to have them remember everything, but it must allow them to remember where they found the information previously.

YMMV, but i'm blown away so far and i haven't seen anyone talking about this along similar lines yet. It all started after reading one too many psychology books.

gbog 6 hours ago 1 reply      
I always wondered if great tools like vim, nmap, git, etc. are successful because they have great documentation, or have great docs because they are successful.

maybe the answer is in the middle and above, great tool makers are great docs writer.

lifeisstillgood 8 hours ago 1 reply      
I am becoming fascinated by finding better ways to document and communicate about code - not just writing good docs as part of checkin but, well lets say we take on a feature.

We should propose how to implement that feature, (spec) get some feedback, go do it, review the implementation against the spec and even then I would want to have a sort of stack overflow Q&A site so people can ask why did you do that ?

Anyone else feel we are missing a whole boatload of tricks?

ef4 4 hours ago 0 replies      
Producing great documentation requires the same kind of judgement as designing the system in the first place: if you can consistently put yourself in the mind of your reader, then your code, your APIs, and your documentation will all be much better.

More documentation is not necessarily better. Just like code, the best documentation is the documentation you never had to write because you found a simpler way, and eliminated the issue completely.

Perceptes 7 hours ago 4 replies      
I agree with this, but have had trouble getting support for the idea of focusing on documentation among my coworkers. The major concern is that comments can rot as code changes and the comments/documentation are not updated to reflect the changes.

It's my opinion that it should just be part of the developer's discipline to update documentation as they update code, but this seems not to be practical when not everyone shares my idealism for documentation. What ways are there to get buy in from those that need to be convinced about the value of documentation?

swalsh 2 hours ago 0 replies      
Its pretty old, but its hard to get better then Doxygen:
taeric 5 hours ago 0 replies      
Every time I face a rant like this at work, I need only fire up an editor and pull up the source code to git. For loads of fun, load up date.c. There is no disputing that git is high quality code that we rely on. My dispute is that odd insistence on rigid documentation standards is silly in this context.

Note, this is not to say that documentation doesn't matter. It definitely has a prominent role. So does "does the job." Preferably well. The blogger mentions a prime lens works because it doesn't allow zoom. Sure it does, you just have to move your feet. This can actually be rather annoying when you are trying to get a candid shot in the house. Framing doesn't automatically happen with a prime lens, that is. However, the quality of image from a prime is huge. More than makes up for the short comings for many of us.

saurabh 4 hours ago 0 replies      
Hey Kenneth, I saw your tweet about wanting a .org for your website. Any reason for the migration to a .org?
Show HN: synchronize saved HN stories with Pinboard github.com
14 points by koevet  4 hours ago   3 comments top
naner 2 hours ago 2 replies      
Well this is a little embarrassing: How does one 'save' stories on HN?

Also it looks like you hardcoded your personal HN saved page url into the script.

       cached 2 December 2012 20:02:01 GMT