SvnHg is a command-line tool to convert from a Subversion repository to a Mercurial one, preserving the whole history of the repository.
FindRepe finds (and optionally deletes) duplicated files by content, not name. It uses MD5 and SHA1 hashes to compare files. It can also compare just by file name.
An IDE for Python.
A preprocessor that compliments the C standard preprocessor.