The greatest change in 0.70 is the license change from GPL to LGPL. Also included are various bug fixes and optimizations.
Various bugs have been fixed to make MString more robust. Additionally, a glob function has been added. Globs are strings where a "?" matches any character and a "*" matches any string. You can use the CompareGlob function to do wildcard comparisons with an MString.
MString .61 has some interesting new additions. The first of these is a double-type constructor. A big new feature is the automatic char * return added by Bruce Riggins. Please help test this new feature.