Info-ZIP portable compression/archiver utilities (Zip, UnZip, WiZ, etc.)
Free 32/64/16-bit multi-platform Pascal and Object Pascal compiler
A 32/64/16-bit Pascal compiler for Win32/64/CE, Linux, Mac OS X/iOS, FreeBSD, OS/2, Game Boy Advance, Nintendo NDS and DOS; semantically compatible with Delphi, Borland Pascal and Mac Pascal (partially) with extra features, e.g. operator overloading.
Versatile Commodore Emulator
VICE is an emulator collection which emulates the C64, the C64-DTV, the C128, the VIC20, practically all PET models, the PLUS4 and the CBM-II (aka C610). It runs on Unix, MS-DOS, Win32, OS/2, Acorn RISC OS, BeOS, QNX 6.x, Amiga, GP2X or Mac OS X machines.
Laser is a multiple arcade emulator available for several platforms. It uses Marat Fayzullin's Z80 and 6502 CPU emulators. It was originally based on Mike Green's SinVader.