When Apple released OS X, it served as a benchmark in bringing together the power of Unix with a cutting edge graphical user interface and desktop. With its support for Microsoft Office and interoperability with Windows, it is a wonder that OS X does not become the “killer desktop” the Linux world has been looking for. However, that is another discussion.
Apple joined the open source community by releasing the Unix underpinnings of OS X, Darwin, and enabling it to operate in an X11 environment (among numerous other open source projects Apple is working on – found here. This brought Linux and Unix (*nix) apps to the Macintosh somewhat like Cygwin has brought running X11 to Windows users. The main difference being the core kernel of OS X is a modified BSD Unix kernel, whereas Cygwin emulates a *nix environment atop the Windows kernel.
Fink has gone one step further by porting 3,583 *nix apps (as of this morning) to run within Fink on OS X. Fink can be found at Sourceforge. The platform can be installed one of two ways, either by compiling from source or via a convenient binary package (in the Debian Linux theme).
With Fink you can fully function in an X11 environment, loading X Windows and X apps as well as expanded sets of terminal applications. This further positions OS X as a comprehensive development environment, with a rich server testing toolset on the localhost and complete access to the full portfolio of your favorite *nix applications.
To make the transition even easier, Fink Commander, also found at Sourceforge, serves as a graphical front end to the Fink packaging. It puts a GUI on the command line tools Fink offers for downloading and compiling *nix apps on your OS X machine.
I found one additional site very helpful in my own use of Fink on OS X, and it includes topics on Fink and Panther (10.3.x) – Sao’s Place – Fink and Apple OS X.