From OSDev Wiki
Other compilers that can be used for OS development:
- Ken Thompson's portable compiler collection for Plan 9, now available in *nix systems as part of the Go toolchain.
- Borland Turbo C - only useful for 16bit OSes - Available from the Borland/Embarcadero Antique Software Museum
- Free Pascal Compiler - available at http://www.freepascal.org. Only issue is that you need to write your own RTL to not call system functions.
- FreeBASIC - 32-bit BASIC compiler (not an interpreter) that has many new improvements that will help in OS construction such as pointers and inline assembly, Available at http://www.freebasic.net
- Intel C/C++ Compiler. Commercial (free 30-days trial). Available for Linux, Windows, and OS X. It is very compatible with MSVC++ (I haven't spent even an hour to change compiler) and GCC (as they say). Famed for it's heavy optimisation. Targets IA-32, x86-64, IA-64, and XScale. Recommended by Intel for systems and applications programming (info on this would be helpful). http://software.intel.com/en-us/intel-compilers/
- PCC/Portable C Compiler - http://pcc.ludd.ltu.se/
- Clang - a front end for LLVM - http://clang.llvm.org/
- Smaller C - may be good for a bootloader since it supports real mode and unreal mode
- Active Oberon - the complete A2-System has been implemented in Oberon, see Language Info in the Oberon Community Platform. See also: Operating System in Wikipedia and Lukas Mathis' Blog: Ignore the Code.
- Digital Mars - mainly known for the D programming language, but also supports C and C++. Commercial and free versions available, targeted for Windows and DOS. Homepage: http://digitalmars.com/
- ToDo: What other compilers can be used for OS development (excluding those listed in Category:Compilers)