What is the latest version of the Boost library that is compatible with Microsoft Visual C++ 6? And can you provide a link to download it directly?
The Downloads link at http://www.boost.org only gives a download for version 1.36.0, and the documentation for that version lists Visual C++ 7.1 as the lowest version of Microsoft compiler tested. Do they purge out downloads for older versions?
Boost 1.34.1 has been tested with vc6. The old versions are still available.
You can get all older versions from the boost download page on SourceForge.
The compilers used for regression tests are probably buried somewhere on the boost.org website.
It's worth noting that Boost doesn't actively not support VC6 either. Most of the boost libs probably still work with VC6 (they haven't stripped out the VC6 compatibility code, as far as I know)
So you could just try 1.36.1 and see how far you get.