Some quick search counts for the catalog:
25 matches for "U.S. and Foreign Release"
67 for "General Public Release"
175 for "Open Source"
212 for "U.S. Release Only"
225 for "U.S. Government Purpose Release"
So a good chunk of stuff is openly available, but there's a lot that could still be opened up.
I attempted to request access to some 3 of their projects and was denied because it was 'Government Use Only' and I did not try pretending I was another Government Agency.
I love the idea but it seems it is not as 'released' or as open as I initially thought it was.
Wonderful; now we can proactively modify Curiosity's code to act as an interplanetary telegraph so Matt Damon doesn't have to do it once he gets stranded there.
Download link of catalog: https://technology.nasa.gov/NASA_Software_Catalog_2017-18.pd...