GRC Release notes:

The development release is the most recent, 
It proceeds the releases with version numbers.

GRC 0.70 is the most current stable release.

0.69 - September 19th 2007
0.65 - March 20th 2007
0.60 - February 8th 2007
0.70 - April 24th 2008

Anything older than 0.65 is deprecated.

The other archives are older versions of GRC. 
GFGG (graphical flow graph generator) was the previous name for GRC, 
but the version numbers are consitent.