I've compiled the AngelScript using the VC++9 project and the release version came up much larger than the debug version. How's that possible? The release version has almost 8 MB size, while the debug has a bit less than 3 MB. I think the release version should be smaller, right? Anyway, I believe 8 MB is too much for a static library.

Is there link-time code generation enabled on the release version? That can increase the size of static libraries by quite a bit. In any case, .LIB sizes by themselves aren't really a big issue. How big is your executable once the static library is linked in?

I don't know because I haven't used it yet, I just found it unusual. I'll come back later.
Thanks.

The size of the binary can also increase a lot if it is optimized for speed rather than size. During this kind of optimization the compiler commonly 'inline' functions and 'roll out' loops, which effectively duplicates the code all over the place.