Photran 9.1 is part of the Eclipse Mars release train, along with version 9.0 of the Parallel Tools Platform. Eclipse 4.5 (Mars) was released on June 24, 2015. A list of new features is available in the New & Noteworthy.
Photran 9.1 requires Eclipse 4.5 (Mars) and CDT 8.7.
Please also join the Photran mailing list; if you have any problems installing or using Photran, that is a great place to ask for help.
Old versions are available in the Photran Download Archive.