A similar tool is sanity.pl (/projects/sanity/) which cleans up spaces (like nsra) and semicolons and umlauts (unlike nsra) from filenames. One or the other project should probably expand into a general tool for doing renaming where you can specify arbitrary Perl code. Larry Wall's 'rename' oneliner works, but doesn't handle recursing through subdirectories (which in this case is a useful feature to add to the tool itself).
(Why isn't there a 'related projects' section of the Freshmeat database? Oh well...)
An open, cross-platform journaling program.
A scientific plotting package.