After a long history of deliberation over the subject, Torr Samaho (lead developer of the Skulltag source port) has finally decided to allow Skulltag to go fully open source. In the past this sort of thing has been debated because of cheating possibilities, but a recent spike in interest over the state of Skulltag's much needed updates put the wheels in motion for a historical moment for Skulltag. With the source released, this opens up a whole new world of possibilities when it comes to features and updates, all Skulltag needs now are some interested developers willing to contribute. You can check out the release thread (which has the source linked) here.