Quote from the site.
Check at the VBA Smooth site. http://vbasmooth.emulation64.com/VBA smooth project canceled
Thanks to Pokemonhacker's hard work, the latest VisualBoyAdvance v1.8b3 with achurch's optimized ARM core works very well. This build can run at full speed with sound synchronization for most of the GBA games in most computers, so I think the future release of VBA smooth is no more necessary.
Everyone can use the source code modification from VBA smooth project for your own purpose, only if you follow the open source spirit to share your code with else. I can't stop you not to do this, but it will be not fair to all authors involved with VisualBoyAdvance project who open his source.