#x11 application time!
This is #xdtm which is a "graphical shell for X". It appears to be a file manager and application launcher combined.
Originally written by Edward Groenendaal, Ramon J. Santiago, and Lionel Mallet, circa 1991 - 1995.
It uses the X Toolkit widgets.
It comes with a standard set of XBM icon files to represent most file types. Some of the builtin application shortcuts assume #csh as the default shell, but this can be changed.
The xdtmrc configuration file has its own grammar, courtesy of a lovely lex/yacc grammar definition.