Gpx-utils is a project mainly written in ..., it's free.
Read .gpx GPS files & print information about them
A Haskell app to read a .gpx file and print the track length.
Tested on Haskell platform (as of Nov 13, 2011). Need to install the 'hxt' package (http://www.fh-wedel.de/~si/HXmlToolbox/index.html) with:
cabal install hxt