Twitter is built on open source software
twitter.github.io
twitter.github.io
In terms of engineering staff, they are the exception, not the norm. A company like home depot or kelly moore paints would have a tough time relying on open source for all their operational software.
EDIT: I added Google because of robots, AI and driverless cars, I'm not really sure Twitter is on that level.
In terms of software engineering Twitter is absolutely one of the best around.
Is doing so wrong?
For vertical software systems, probably. For applications developed in-house, I'm guessing that even at Home Depot or Kelly Moore it's the other way around -- more and more, you have to make a good case for using a proprietary library. The connotations of "open source" have changed somewhat, and open source libraries are becoming the norm, even at large old-school software businesses, where the lawyers hate open source.
I think close to 100% of the internet is built on/with open source software.
But it's a major headache to get your in house libraries/software released as open source. There's reservations because by default everything developed is considered proprietary and a trade secret. It's difficult to convince management to give stuff back and/or see a benefit, the larger the org the harder it gets. Then comes legal with the legal derp.
And finally you can't just put stuff on Github and expect it to thrive, you need resources to maintain your open source projects and again convince management beforehand that it's not just a liability.
The only one I can see is building culture/name for yourself (which I don't consider a trivial thing), but I can't think of anything else.
You probably mean this [1], but all I see is this [2]. What's wrong with me?
[1] http://www.urbandictionary.com/define.php?term=%3C3&defid=11...
[2] http://www.urbandictionary.com/define.php?term=%3C3&defid=13...
Think about this: if Twitter open sources 100% of their code, what would change? Would Twitter clones pop up all over the place? No, because Twitter is the software + infrastructure + name. Most companies think that their code contains some type of secret sauce that makes it special. In reality that's not true. Sure, Google may hide their exact PageRank algorithm, but they don't need to hide their web server code. Or their indexing algorithm. Companies like Twitter are even better for this: they do absolutely nothing that's really proprietary.
For an example of this on a much smaller scale look at TheTVDB (http://thetvdb.com/), their entire site source is OSS, yet there are no clones.
IIS is still quite widely used for many web sites. Netcraft's latest survey results suggest just slightly under 30% of all web sites are served by it. So that's some closed-source software powering a significant portion of the web, at least.
And it's quite safe to say that those IIS installations are running on some variant of Windows, which is yet another generally closed-source software system. Then there are other non-web services (DNS, FTP, and so on) handled by such Windows systems.
There are still a surprising number of proprietary UNIX systems out there in production, on the public Internet. We're talking HP-UX, AIX, UnixWare, and even BSD/OS in some cases. There are many behind the scenes, indirectly supporting web sites and other publically-accessible services.
There is a lot of other networking gear that runs proprietary software, too.
Is open source software important to the Internet? Absolutely. Is it the "100%" you're claiming? Absolutely not.
There's some high profile exceptions like the infrastructure parts you mentioned, but noone expects you to open source your router and unix config, there's nothing worth contributing and collaborating on here.
Anyone who is interested in Twitter's current open source contributions should definitely check out the open source section of their engineering site as well:
Keep up the great work guys.
They key difference between Twitter and a would-be competitor is scale (and that's why the actual mechanics are not simple at all), but you don't get to that scale on the strength of technology alone. More importantly, once you're at that scale you become exceedingly hard to dethrone, for primarily non-technical reasons.
That is why Twitter can afford to be extremely generous when it comes to releasing IP. Of course they don't have either, so thanks Twitter!
I'm more familiar with Google's contributions, but I would imagine both high-user-visibility projects like Android and Chromium and more developer-oriented projects like protobuf, the Closure Compiler, the Dart and Go programming languages, googletest, Guava, Guice, WebM/WebP, V8, Breakpad qualify. I could consider all of these "projects that are applicable to a large group of people". This, on top of large contributions to other key projects like the Linux kernel and LLVM.
I know less about Facebook's contributions, but I do know that their open source projects includes HipHop/HHVM, and they contribute significantly to Hadoop, LLVM and Mercurial (among other high-profile projects).
For Google, it would be much harder, as they use so many proprietary (backend) technologies, GFS, BigTable, Chubby etc.
https://github.com/google/gumbo-parser
(And LevelDB, Snappy, Angular, GoogleTest, tcmalloc and google-perftools, lmctfy, etc.)
The first rule of the Twitter bird is: You do not change the form of the Twitter bird.
The second rule of the Twitter bird is: You DO NOT change the form of the Twitter bird.
The third rule: If someone Tweets without referring back to Twitter, the game is over.
The fourth rule: No speech bubbles, no inadequate portions of space around the bird
The fifth rule: If this is your first experience with the Twitter bird, you have to Tweet with Twitter.
"This repository is published in order to share code and information and is not intended to be used directly outside of Twitter. We provide no guarantees of bug fixes, ongoing maintenance, compatibility, or suitability for any user outside of Twitter"
It was a strange experience to scroll down, see something that sounded interesting and then end up at a repo like that.
For example, go to https://github.com/twitter/twitter-text-js and click on the red bar.
More info at https://github.com/blog/1037-highlighting-repository-languag...
Thanks Twatter!