Homebrew is a package management system

Package management system

In software, a package management system, also called package manager, is a collection of software tools to automate the process of installing, upgrading, configuring, and removing software packages for a computer's operating system in a consistent manner...

 that simplifies the installation of software on the Mac OS X

Mac OS X

Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...

 operating system. It is a free

Free software

Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...

/open source software project to simplify installation of other free/open source software. It is similar in aim and function to MacPorts

MacPorts

MacPorts, formerly called DarwinPorts, is a package management system that simplifies the installation of software on the Mac OS X and Darwin operating systems. It is a free/open source software project to simplify installation of other free/open source software...

 and Fink

Fink

The Fink project is an effort to port and package open-source Unix programs to Mac OS X. Fink uses dpkg and APT , as well as its own frontend program, fink ....

. It was written by Max Howell and has gained popularity in the Ruby on Rails

Ruby on Rails

Ruby on Rails, often shortened to Rails or RoR, is an open source web application framework for the Ruby programming language.-History:...

community and earned praise for its extensibility.