Not yet; at this time, the xPDO implementation for PostgreSQL and SQLite is still under development. I had hoped to get some collaboration on this development, but up until now it’s been just me working on it. Once we release MODx 2.0, this will become a higher priority for me and I expect that a point release of MODx Revolution 2.x soon after will introduce PostrgreSQL and SQLite support.
I know xPDO is integrated with 2.0 but does that mean I can run the Modx software off of a Postgres install?
The status is the same; I’ve not had the time to invest in developing the xPDO PostgreSQL implementation, nor do I have any experience with it. And why would you re-work the core of 0.9.6 to build a custom shopping cart? Regardless, you would need to become familiar with xPDO and MODx 2.0 in order to contribute the xPDO PostgreSQL support; this has very little in common with 0.9.6.x/1.0 (aka Evolution).
I’m actually in need of Postgres support for a client as well and was wondering what the current status is on this? I could help develop it out a bit. I actually re-worked the core recently to build in a custom shopping cart solution. I’m very familiar with the framework for 0.9.6 but not sure if that does much for 2.x.