ARM7TDMI and Oki Advantage Microcontrollers are currently fully supported by GNU public domain software development tools. There is complete C, C++, Assembler, linker and debugger available which is supported on Windows as well as Linux systems. There is also comprehensive documentation available on GNU's ARM support.

For more information about GNU tools for ARM please refer to sites such as www.GNU.org or www.redhat.com. Also ARM Developer Zone (www.armdevzone.com) has very good information on this subject.