I have a branch that adds a printdepversions that prints (if knowable) the header and binary versions for each of our external library dependencies. I don't think it's a good idea to merge it as-is though: it may be fragile to ensure that the #include always matches the file where the library is actually used, lest you get different results while having more than one version installed. Also including that many headers in one file is likely to result in macro conflicts and stuff.

So I have a new idea: store the version info in ROM cvars, e.g. version.sdl.header for the SDL header version and version.sdl.binary for the binary version. Then the cvar for a given library can be populated from the file where it is primarily used (even in gamelogic). Also this is more flexible w.r.t. stuff like alGetString(AL_VERSION) which actually requires a valid context to work, so it is not always available. To list all the versions you can do /listcvars version. or there can be a convenience command. What do you think?