Starting with version 5 the code base is split in two forms of repository.
The Narayana code base (i.e. version 5 and above) is maintained over on github.com.
The url to access the source code for this and future releases is from here:
Note, that if you want to contribute code back to the project, you will need to fork the project as raise a pull request in the same manner as other git projects. The AS7 team have put together a handy guide on how to use git to raise pull requests, we recommend you follow/contribute to that guide as we try to maintain relative consistency with their approach to version control.
The guide may be accessed from:
Legacy JBoss Transactions (version 4.x and below)
Anonymous Access URL
Secure Developer Access URL