I have just released PBXT 1.0.11, which I have titled "Pre-GA". Going by our internal tests, and all instances of PBXT in production and testing by the community this is a GA version!
However, although PBXT has 1000's of instances in production, it is not used in very diverse applications. So I am waiting for wider testing and usage before removing the "Pre" prefix.
You can download the source code from primebase.org, or pull it straight from Launchpad. Here are instructions how to compile and build the engine with MySQL. PBXT builds with MySQL 5.1.46 GA, and earlier 5.1 versions.
If you don't want to compile it yourself, PBXT 1.0.11 will soon be available in the 5.1.46 release of MariaDB. And, for the more adventurous, PBXT 1.1 is included in Drizzle.
A complete list of all the changes in this version are in the release notes.
If you are testing PBXT and have any questions send me an e-mail. I will be glad to help.
And, oh yes. If you are looking for development or production support for MySQL/MariaDB and PBXT then please write to: support-at-primebase-dot-org.
We are working together with Percona and Monty Program Ab to provide the service level you require.