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.
NES/Famicom emulator based on FCE Ultra.
An updated Mac OS Classic/Carbon-specific port of FCE Ultra 0.98.13, the Nintendo Entertainment System/FamilyComputer emulator, and beyond. This emulator is meant for older Macs, pre-OS X.
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.
BlitPixie is a collection of optimized software blitters, written in assembly language or normal ANSI C. They perform a lot of normal pixel moving operations, and all work in 8/16/32-bit depth.
Antique Finder - open source Finder clone based on Finder 1.1g
The Gryphel Emulator emulates a Macintosh Plus and other of the earliest Macintosh computers. It can run old Macintosh 680x0 software that otherwise couldn't be used on recent machines.
MacMPEG2Decoder (aka MM2D) decodes MPEG2 video into a variety of formats, normally quicktime based, on a Macintosh (Classic & OSX).
A Interactive Network VideoGame
The TruongQuangDuocIDS (tqdids) is an IDS that works on multi-platform, from Solaris/SPARC to HP-UX/Alpha. This IDS has features like other IDSs (snort etc.) but it has a special feature inside the binary-pattern-matching algorithm that makes it faster.
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.