The Ubuntu Phone team have moved to Raring aka Ubuntu 13.04 (to be released later this week). Sergio Schvezo writes on the mailing list:
Hello everyone, just wanted to shout out that raring is now the default build that you will find on cdimage, it’s actually the only build, you will see no more quantal builds as of today.
If you use phablet-tools to download, make sure you have 0.11.*\ or greater.
The latest quantal has been tagged and can be seen by doing:
In addition all the build scripts are in the open if you are looking into replicating, albeit they would need some adaptation to get it working smoothly on a new environment, those are located in  and . As with
everything, MRs are welcome.