Download:

GONG Ring Analysis pipeline: a tar file with README file explaining installation.
Reading Inversions: an IDL code that reads the inversion output from the pipeline.

The software is also made available through HELAS Local Helioseismology Network Activity hosted at MPS (Max Planck Institute for Solar System Research) 

Reference:

Corbard, T., Toner, C., Hill, F., Haber, D. A., Bogart, R. and Hindman, B. "Ring Diagram Analysis with GONG++", SOHO 12 / GONG+ 2002, ed. Sawaya-Lacoste, H., ESA Special Publication, Big Bear (CA, USA), 27 oct -1er nov 2002, vol. 517, p. 255  (2003)

Documents associated with this software :

ps

Ring Diagram Analysis with GONG+

Documentation for the Tracking and remapping steps

pdf Inversion for ring diagram analysis in GONG++ Pipeline
Presentation at the LoHCo meeting, Tucson 2004
pdf Ring Diagram Analysis Method and Tools
Presentation given at the HELAS Workshop in Nice, 2006