This is one of the most popular Doom source ports. It is available for DOS, Windows, Linux and Mac OS X, and should build on any POSIX platform which supports SDL. It enhances Doom with things like TCP/IP networking, OpenGL renderer, Heretic support and much more.
Antique Finder - open source Finder clone based on Finder 1.1g
Lamp is a Unix-like environment that runs in a single process (via threads) on traditional Mac OS, including standard I/O, vfork/exec, a shell, perl, sockets, virtual fs with /dev and /proc, signals, and ptrace(). Runs on 68K/PPC, and on OS X as Carbon.
MacMPEG2Decoder (aka MM2D) decodes MPEG2 video into a variety of formats, normally quicktime based, on a Macintosh (Classic & OSX).
A Interactive Network VideoGame
vMac is a free Open Source Macintosh emulator that is available for Linux/X-Windows, Win32, DOS, MacOS, and more.
The purpose of wxSSL is to allow wxWindows programmers to write SSL programs using socket classes similar to what exists in the current wxWindows. wxSSL will implement the IPC and socket classes over SSL.