The original version of the backend protocol is free and open source: http://github.com/supertestnet/hodlcontracts

I am currently revising the protocol and will release a new free and open source version when it is ready.

I don't think decentralized escrow is possible. The best I could probably do in the future is a federated oracle, where a group of people (e.g. 11 of 15) have to agree that some real world event happened in order to release the funds. But federations also have their downsides compared to just picking one person to trust.

Instead of making a decentralized escrow, what I hope happens is that lots and lots of people run an escrow service so that bitcoiners can choose from among them. Imagine if Marty Bent, Matt Odell, Stephan Livera, and many others all ran an escrow service and you could create an escrow contract using any of their nodes as the trusted party. (All non-custodial of course.) A bunch of independent centralized escrows could perhaps be just as good as one decentralized one.