A Tap is homebrew-speak for a git repository containing extra formulae.
Homebrew has the capability to add (and remove) multiple taps to your local installation with the `brew tap` and `brew untap` command. Type `man brew` in your Terminal. The main repository https://github.com/Homebrew/homebrew often called "Homebrew/homebrew" is always built-in.
* [homebrew/apache](https://github.com/Homebrew/homebrew-apache): A tap for Apache modules, extending OS X's built-in Apache. These brews may require unconventional additional setup, as explained in the caveats.
`brew search` looks in these main taps and as well in [Homebrew/homebrew](https://github.com/Homebrew/homebrew). So don't worry about missing stuff. We will add other taps to the search as they become well maintained and popular.
You can be added as a maintainer for one of the Homebrew organization taps and aid the project! If you are interested write to our list: homebrew@librelist.com. We want your help!
* [InstantClientTap/instantclient](https://github.com/InstantClientTap/homebrew-instantclient): A tap for Oracle Instant Client. The packages need to be downloaded manually.
* [besport/ocaml](https://github.com/besport/homebrew-ocaml): A tap for Ocaml libraries, though with caveats, it requires you install its customized ocaml formula. Perhaps a template for more work.
* [osx-cross/avr](https://github.com/osx-cross/homebrew-avr): GNU AVR toolchain (Libc, compilers and other tools for Atmel MCUs, useful for Arduino hackers and AVR programmers).
* [nddrylliog/homebrew-mingw](https://github.com/nddrylliog/homebrew-mingw): An experimental port of Homebrew for Windows (with an MSYS/MinGW environment).
