The "ports and adapters" architecture (aka "hexagonal architecture")

Atomikos is designed along the ports and adapters/hexagonal architecture as described here by Alistair Cockburn.

Among other things, this means that it is relatively easy to:

• Implement new transaction APIs / standards / models
• Add new types of two-phase commit resources

Examples of things we've been able to realize thanks to this:

• JTA (port) / XA (adapter)
• TCC (port/adapter)
• RMI (port/adapter)

The port and adapter model is also an important concept in the new book Implementing Domain-Driven Design. Our domain is 2-phase commit. Our adapter is our Participant model. Our ports are all the ways you can interact with our core system.