One difference that I am aware of is that OpenTransactions uses the Bitcoin blockchain and the other two are supposed to have their own blockchain. But it's hard to get details of how these things are supposed to work.
It's not hard. It's time consuming. Scouring 9 different semi-curated resources to develop a clear and concise comparison of the 3 is quite a task, a task someone should take on if any of these technologies are to become mainstream. How would you summarize the differences between them?
If you are able to extract concrete, detailed information about these things from their wiki, blog and forum, congratulations. I can't. It all sounds pretty vague to me.
This exactly. I think part of the problem is that each of these projects has a corporate backer, Monetas, sponsoring Open Transaction is building a business around the platform. There is some incentive to keep the best doco closed source. There is a slim to none chance that the only documentation Monetas is using is available publicly. I spent some time setting up an opentransactions server, but could never spend enough time/research to get a production server up.
