Thank you for donating apparently very useful software. For device like set top boxes, you may have just made VIA a much more viable (pardon the pun) option.
By the way, I feel the need to apologize for some earlier posts on this forum, not written by me, that might (hopefully unintentionally) seem to thanklessly ask you to justify why you didn't work on the poster's preferred project instead. I hope and assume it wasn't the intent of that commenter to come off that way, but I do want to speak up and say that that is certainly not how I, for one, feel about your contribution. I think it's great when anyone takes the time to publish free software, especially something that demonstrates some bits of possibly insightful new software design that others can study.
To that end I have compiled your driver against both xorg-server 1.4.x and 1.7.x, a surprising painless process given the substantial interface changes between the two versions. Unfortunately, xf86-video-unichrome seems to have some problems DDC on my hardware while openchrome seems to work fine, which makes me wonder if you have any thoughts on how hard it would get unichrome to the hardware and feature coverage of openchrome or, alternatively, port your XvMC support to xf86-video-openchrome. In any case, I look forward to further studying your new XvMC support code. Thanks again for writing it.
About the compatibility with many X versions, this is sadly something that only old-school driver developers do. One of them, Thomas Winnishhofer, the SIS driver developer, sadly gave up on development years ago. I pretty much am the only one of this kind left.