BOMB Studio was the application framework I used when I was coding in C. It was cross-platform, since I built it on top of the already existing Vortex framework, which had been coded on DOS, Windows and VMS. BOMB Studio mainly included a software renderer, and a myriad of useful libs one always needs (to load files, compress things, read the keyboard or move the mouse, you get the point). I used that framework in several apps (implicit surfaces for example), without having to recode anything. Basically this was just a handy (big) helper
That project died the day I moved to C++. I still used it a few times to quickly build minor test applications. For example I used it in 1999 to build some basic samples for my V5 Conferences. Nowadays however, this is completely obsolete.