Hi! So, first of all, I think I need to make the description of Goblins clearer. It says "A transactional, distributed actor model environment", but "transactional" and "distributed" are two separate components. This follows the "vat turn" communicating event loop model of E, where every message handling in an event loop is done in a transaction. It isn't meant to say distributed transactions. You can build distributed transactions a couple of ways though: as an abstraction on top of the distributed object system provided, or as a consensus model where a quorum of nodes agree on the order of messages for a deterministic vat/event loop.

By the way, the "open source version of E" does do distributed garbage collection, but it can't collect cycles across a network barrier. However, the original version of E did collect cycles across the network too: http://erights.org/history/original-e/dgc/

However, you needed hooks into the garbage collector for it to work, since you had to do some introspection of how things were rooted iirc. Mark S. Miller told me that originally they thought this could be fixed because Sun had promised to make Java open source, but they took a damn long time to do it. In the middle period, apparently the E folks said "please! just take this patch... you can have it even!" but Sun didn't merge it.

But Mark also told me that he learned not to push for this, because the cycles-across the network stuff turned out to not be common enough to bother, and you could build distributed acyclic gc using just weakrefs (and weak maps) and gc finalizer hooks, which are much more common than the rooting-introspection stuff.

Not sure if I got all that right, but there you go.

Anyway, I'll fix the tagline for Goblins for next release to make it clearer. Thanks for the feedback.