As Juanito is asking, hre's the list of tools for developing/compiling extension:
* sstrip - strip an extra more kilobytes from your binaries. useful if you inted to make tiny extensions/programs
* tcc - another compiler can be very useful while developing. Tcc is small, ultra fast. Its ability to run C files as if they were scripts is super useful.
* fltk-config
* fldev - an fltk IDE well suite for the development of small C/C++ projects. I had fldev working on DSL and I liked it a lot. (I wanted to post an extension back then but my old PC died during last summer)
* fluid - I think there was even a small change in fldev archive that made it possible to optionally integrate it with fldev
I think the ^thehatsrule^ has a good point when he notes that compiling and developing your own stuff are different activities. If fluid/fldev is too IDE-ish or developer centric compared to the compile tools, then I can make a separate IDE extension for those. Let me know what you think!