Up to this point we've covered the core engine component, the local JTA, and then the JTS and remote JTA implementations. That leaves XTS: the Web Services transactions component.
There has been a Web Services transactions component in JBossTS since it's HP days, when it was called HP Web Services Transactions (HP-WST). Once again it was the world's first Web Services transactions product. At that time it was based on the OASIS Business Transactions Protocol (BTP), which didn't get the support of major vendors. Over the intervening years we tracked, authored and influenced BTP, WS-CAF, WS-T and then WS-TX. Each time, we used XTS as the platform for testing these protocols.
Just like the local JTA and JTS implementations, XTS leverages the core engine. It has no dependency on CORBA. It has no dependency on JTA. As well as webMethods, others have used XTS successfully in the past too. Because all of the various Web Services transactions specifications/standards have included support for extended (non-ACID) transactions, XTS is able to exploit yet more of the power of the underlying core engine: the ability to relax all of the ACID properties in a controlled manner. So unlike other vendors, we have the same core engine providing the support for all of the transaction models!
Then of course there's end-to-end transactions (E2EX as we were calling it in HP). We've been talking about transaction bridging for many years and working on one prototype or implementation after another. But the recent work that Jonathan et al have been doing has really pulled everything together into a more coherent approach, at least as far as JEE is concerned.
I could say more about the architecture of all of our components. I could also wax lyrically about recovery or extended transactions. But most of what I'd say is covered by the various hyperlinks I've embedded throughout these entries. So please follow them and read up. If you've got any questions or comments, put them against the relevant entry or post in our forums. But overall, enjoy using JBossTS as much as we've enjoyed developing it over the past 20 years.