We're really sorry about how long it's taking, but there's a bunch of good reasons why the Linux version is taking so long and it has everything to do with the many cool things we're doing to D:OS for the moment (but which we're not ready to announce just yet)
Without going into too much details, here's the story:
First of all, we don't want to use a wrapper like Wine. We want to do it properly, but our own ambitions have been causing us quite a lot of pain.
Since the Linux version wasn't intended to be released on the day of release (we were clear about that from the beginning I hope), little work was done to it prior to release. The reasoning was that if we got the Mac version working (which we didn't expect there to be for release either), the step to Linux was going to be small.
Once we recovered from release and started getting serious on the Linux version, we discovered a truckload of middleware problems, including the non-existence of something we thought existed and the fact that most vendors consider it a separate platform for which they charge extra.
In an ideal world, we would've checked all this sooner, but we didn't, assuming that it was covered. To fix this, we needed to make pieces of middleware ourselves, and so we did. Obviously that delayed things a lot. (The alternative was the wrapper, but we didn't want to do that as we wanted our engine to natively support Linux)
By the time we sorted out the different problems with the middleware, we had two branches of development going because obviously we were doing other things too.
The Linux version was being built on an old branch but ran out of synch with the new branch where plenty of improvements were happening and so we decided to stop integrating it in the old branch and instead focus on the new branch only.
If we wouldn't do that, then Linux would only have been supported on the old branch, and that didn't make a lot of sense going forward, especially since we wanted it to be part of our core engine. Supporting both branches wouldn't have worked since our Linux team is small.
All this wouldn't have been such a big problem if not for us starting to doing something *cool* on the new branch that quickly ran out of hand because we really liked it. So much work ended up being done that the new branch became a lot bigger than we'd anticipated and so it's all taking longer than we thought.
As long as we're not ready, we can't finalise the Linux version and release it. Obviously we've been offering refunds to people who backed with the express intent of playing int on Linux, but so far most in the Linux community seem to have been content that we're trying to integrate it into our core engine such that our future offerings will also include Linux support. It's something we really appreciate.
The long Linux delay is unfortunate but we think a lot of players are going to be really surprised and happy with what we're working on, and hopefully we'll be able to continue to support Linux over different games as a result of the effort it's taking now.
Anyway, it's a long story but the bottom line is: it's coming and we're working hard on making it good.