but due to the language / libraries and IDE used, there's no point in opening the source source. You'd need at the very least $2-3k worth of licenses to even be able to participate in such a project. It's also a multi-threaded 120kloc beast, further limiting the number of people who'd be able to participate. More to the point, we're not seeking help from third parties so late in the development cycle.
Our current projects are built with a more sane/free language, so opening their source code (at some point) is an option we're considering.
However, we have no plan to make our games free, as it's our livelihood and UG took years to develop.