My primary language is C, and all projects are for embedded products. I use compilers from Borland, MicroSoft, Tasking, gnu-gcc, DigitalMars, OpenWatcom, and others.
Assembly language is used as well, with languages including x86, ARM, 8051, 8051XA.
Other files edited are documentation, batch/make, configuration, build, files.
The support for adding error-parsing is extremely useful because of the variety of tools used.