Phabricator, a software fabricator
Phabricator is a suite of web applications that help software companies communicate about software effectively. It was created at Facebook. Phabricator is also used at many other companies such as Airtime, Asana, Dropbox, deviantART, MemSQL, Path, Quora, and more.
Facebook engineers rave about Phabricator, describing it with glowing terms like "okay" and "mandatory". Experience more uncoerced community interaction on Facebook. Review Code
Review others' code with Differential, because they can't be trusted. Shows code so you can look at it. You can reject code if you don't like it. Code review is a pretty okay idea. Fewer bad things will happen if you do it. Example: D212
You can keep track of all the defects and problems in your awful software with Maniphest. Keeps track of bugs. You can assign them to people. Maybe you could fix them eventually. Example: T128
This feature is pretty amazing, you can browse source code on the web with Diffusion. Unnerving. Shows commits. Has shiny colors. Works with Git, Subversion and Mercurial. Example: Phabricator Repository
Also Has A Wiki
You can write things down in Phriction, like this example recipe document where I misspelled dessert. Write text. That text stays there. You can read it later. You can make text bold. Example: March 2012 Changelog
There are more applications too! Who knows what you might discover?
Raise the Signal-to-Noise Ratio
As your company scales, keep track of things you care about with features like Herald and Flags. Write business rules. Everyone loves business rules. Keep an eye on those suspicious interns. Several different flag colors.
The Arcanist command line tool gives you CLI access to most of Phabricator's functionality. Many cryptic commands. ANSI color, where supported. Runs on Linux, Mac and Windows. Documentation: Arcanist User Guide
The Conduit API allows you to write scripts that interact with Phabricator over an HTTP JSON API. Is an interface. For application programming.
Phabricator is under active development. Most patches make it better. Only some break it. Written in PHP, so literally anyone can contribute, even if they have no idea how to program. Even babies and dogs can contribute.
Light Hearted, Heavy Duty
The work these tools do isn't the most rewarding part of anyone's job, but it is important. They are serious, heavy-duty tools -- they just try not to make this stuff suck more than it needs to. Simple, lightweight workflows. Performance is a priority. Tools emphasize collaboration, not process. Infrastructure is serious, scalable and secure.