- SDCC is an open source C compiler for microcontrollers. It can output z80 assembly. However, as the compiler is retargetable, the code is very bloated and inefficient.
- z88dk is a derivative of SDCC. It is targeted specifically at the z80 line of processors and even has dedicated TI file format outputs. Again, the code is still very bloated, because the compiler is based on SDCC.
- The HI-TECH Z80 C Compiler is a very old and unsupported compiler by HI-TECH that produces much better-quality code than the two compilers mentioned above. However, HI-TECH has discontinued this compiler and it is very difficult to obtain a copy. Furthermore, it is a commercial, not open-source, compiler, so using it without a license is of questionable legality.
- TIGCC is the original C compiler for 68k calculators. It is a patched version of the GNU Compiler Collection, and only supports C.
- GCC4TI is a 2009 fork of TIGCC.