thanks for that. also, it's worth noting that the licence for ne04j changed recently - the community edition is now GPL rather than AGPL, so it can be used to bootstrap web services for free (if you ever do need to upgrade to the paid-for version then you are hopefully at a scale where you can start charging customers and paying for software).
[i'm not connected to neo4j in any way; i was interested in using it a while back (for what might have become a commercial project), but was discouraged by the agpl licence, so thought i'd share the good news]
Yes. The Neo4j community edition is always free, and as long as your code is open source, the enterprise edition is also free even for commercial use (http://neo4j.org/licensing-guide/).
[i'm not connected to neo4j in any way; i was interested in using it a while back (for what might have become a commercial project), but was discouraged by the agpl licence, so thought i'd share the good news]
[ps and sqlalchemy is awesome too!]