In boost, the default behavior is to remove not only all text before the last "/", but to remove all text after the first "." from the end (i.e. the file extension or suffix). In GNU and POSIX, the suffix is not removed. In PHP and Bash, the suffix is removed only if specified as an optional 2nd parameter. Whats the rationale for boost having different behavior than the above implementations? It causes a bit of a compatibility/portability issue if someone using GNU/POSIX replaces all basename functions with boost's. Chris