The Small Device C Compiler (SDCC), targeting 8-bit architectures
SDCC is a retargettable, optimizing standard C (ANSI C89 / ISO C90, ISO C99, ISO C11 / C17, ISO C23, ISO C2y) compiler that targets a growing list of architectures: STM8, MCS-51, DS390, HC08, S08, 6502, 65C02, Z80, Z80N, Z180, Rabbit, SM83, TLCS-90, eZ80, R800, Padauk PDK14 and PDK15 microprocessors. There also is incomplete support for the Microchip PIC16 and PIC18 and the Padauk PDK13.
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, Android, 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.