thanks for your interest! glad to hear that.
the tags we made last year are early previews, the current state of master is looking very good especially around MongoDB support.
We plan to tag a new version somewhere at the end of next month; I would say it's better than what we would generally label as a beta, still I think we'll flag it as beta as it's the first in a long time and we know most people won't test master. Maybe it should be flagged alpha but we don't feel that's needed.
I wouldn't throw it into production yet, maybe in a month or two, but if you could start testing it today and provide us with feedback that would be highly appreciated. As usual, help is very welcome; this is also a perfect time to join the team of frequent contributors and committers if you want to, but if you don't have time to look into the code even just sharing your use cases or blogging about it would be nice and motivating.
Mapping of any kind of relation and all CRUD operations on MongoDB are stable now in master; support of queries is still poor but the new query language parser is being integrated this week so we expect support for queries in MongoDB to come soon as well; in the meantime simple queries can be implemented using Hibernate Search.
Looking forward to hear about your experiments!
but it seems like that the directions have you pull in a development snapshot instead of a library you install as a module, so I was a little confused by that.
I'm sorry I didn't understand this part. For sure if you want to try some version, use version 4.0.0-SNAPSHOT, we update it weekly with fresh builds while the latest v.3 tag is much older.