The 0.2.0-incubating release of Apache S2Graph has TinkerPop support. They've just updated their documentation to include this information:
https://github.com/apache/incubator-s2graph#tinkerpop-support I think they meet our index listing policy at this point and we can get them added to the home page. If there are no objections, I'll assume lazy consensus after 72 hours and get them added.
