 Like other NXT languages, ROBOTC requires this firmware to be downloaded from the ROBOTC interface in order to run.NXTGCC is a GCC toolchain for programming the NXT firmware in C.

leJOS NXJ is a high level open source language based on Java that uses custom firmware developed by the leJOS team.To be able to write in C/C++, nxtOSEK can be used, but that requires custom firmware too.