FreeXL  1.0.6
Other tools and libraries

There an impressively wide choice of Free and open source libraries and tools supporting the .xls format.

A sample:

A quick critical review:

Conclusion: a suitable C/C++ library supporting data extraction from .xls files doesn't seem to exists: or at least, there is no obvious reference choice.

So we'll go on the hardest way, we'll develop yet another .xls reading library: FreeXL.