There is only one file type that uses the .TMPROJ extension:
TextMate Project File
Project file created by TextMate, a Mac text editor that supports editing and syntax highlighting in many programming languages; saved in an XML format and contains references to project files; also stores the currently opened file, preferences, and editor window settings.
TMPROJ files are used for organizing source code files together in a project.
Updated: September 29, 2011