The current development environment for the MySQL version of the WACS system is based upon MySQL release 5.0.45 as provided with Fedora 8 Linux. Some of the more advanced features in Wacs require nested selects to be supported, a feature that was introduced to MySQL after the conventional 4.x series releases. Anything with version 5 should be OK and it's possible that it will work but with some limitations on version 4.

The current development environment for the Oracle version of the WACS system is based on the x86_64 version V11.1.0.6, but retaining support for Oracle 10; the upgrade to Oracle 11 happened at Wacs release 0.8.4. We are not aware of any features that Wacs requires that don't work in Oracle 9, 10 or 11. There might be some problems on Oracle 8 or older due to issues on getting table structure meta-data for the perl DBD driver.