OrientDB looks very attractive from a functionality+license standpoint. I haven't been able to google up much in the way of reports by people who have used it. Can anyone cite particularly notable successes or failures?
We are using OrientDB for an enterprise notary system and is fast as hell! We try other relational options but since we are storing and retrieving documents we go instead for this one.
We are using currently Java for the backend and front end have a web interface (Java Server Faces where we use the Orient REST and JS API's), and also an smart client (built with WPF + .NET 4.0, using a custom Java wrapper API for its use with .NET). Why did we choose OrientDB? Well, primarily because of a friend of mine who recommends me to use it. Then our IT dept. do some testing and benchmarking and approve it).
The only "delay" was building the wrapper for C# but no big deal.