- SDCC is an open source C compiler for microcontrollers. It can output z80 assembly. However, the code is bloated and inefficient.
- z88dk is a derivative of the Small-C compiler. It is targeted specifically at the z80 line of processors and even has dedicated TI file format outputs. The code is very bloated and can be less efficient than 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 (Although recent SDCC versions are able to generate code comparable to the HI-TECH C compiler). 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.