sgasm is a simple generic Assembler that is easy changeable for your own vm's instruction set. It supports many types of instructions, parameter types, Offset-Jumps and so on. It is also very fast and platform independent.
TAMC is a source-to-source translator that generates Fortran routines for computation of the first-order derivatives out of Fortran routines.
Table Driven Assembler is a free portable cross assembler for any kind of assembly language. It should be possible to use it as a compiler to any target microprocessor using a table that defines the compilation process.
The Amsterdam Compiler Kit
The Amsterdam Compiler Kit is a fully-featured retargetable compiler toolchain. It supports backends for the 6500, 6800, 6805, 6809, ARM, i86, i386, i80, Z80, Z8000, 68000, 68020, 68040, Sparc, NS16032, Vax, and PDP 11 architectures and many different platforms. It supports frontends that will compile K&R C, ANSI C, Pascal, Modula 2, Fortran, Occam, and Basic. It provides a complete development environment including preprocessors, compilers, assemblers, linkers, librarian tools, and target download tools.
TinyCOBOL is a effort to develop a free COBOL compiler with basis in COBOL 85 standard. TinyCOBOL generates a GNU assembly code at output that works in IA32 platforms.
Ulm's Modula-2 System
Ulm's Modula-2 System is a software development environment for Modula-2 which runs on several UNIX systems. The system consists of a compiler which is derived from the 4-pass Lilith Modula-2 compiler of the ETH Zürich and conforms to [PIM3], a library which interfaces UNIX system-calls and provides system-independent abstractions for input and output processing and ASCII-terminal based windowing systems, a set of tools for generating and updating makefiles, debugging, and profiling, and documentation in the form of manual pages and this document.
WLA DX is yet another macro assembler that can program the GB-Z80, Z80, 6502, 65c02, 6510, 65816, HuC6280, and SPC-700 CPUs. Included in the package there is a GB-Z80 disassembler and few converters.
X11-Basic is a non-standard Basic interpreter with full X graphic capability and some other special features. Syntax is most similar to the old GFA-Basic ATARI ST implementation.