This post is an update to my last post related to GraphDB marketshare (posted more than 2 years ago.) After 2 years, how have the GraphDB Communities changed? Twitter followers, reviews, etc can be bought/falsified.
But with an Open Source project, with open communities, I found a metric that is very hard to cheat: participation in groups. Then I discovered that Google Groups already provides this metric.
Below find the Neo4j and OrientDB charts.
It's very cool to see that not only is the OrientDB community very active on Groups, noting that OrientDB also has other channels (Chat, StackOverflow, etc.), but OrientDB is actually more active than Neo4j. In the past month, October 2014, OrientDB had 472 posts compared to 351 posts on Neo4j.