VirnetX claims to have patents covering the P2P mechanism behind the original FaceTime.
Originally it worked similar to iMessage in that you had a system to exchange identities but the actual communication was all P2P after that.
Apple had to change it to use their servers to get around the patents (which VirnetX claimed wasn't enough and was still infringing).
Once that changed there was no point in releasing it as an open standard since it required Apple's servers to operate.
If VirnetX prevails then Skype, Google Hangouts, and everyone else is infringing too and VirnetX will use the precedent to go after them as well. It's a common strategy: go after a couple of people first, establish a win, then use that to leverage settlements out of the remaining players.
Originally it worked similar to iMessage in that you had a system to exchange identities but the actual communication was all P2P after that.
Apple had to change it to use their servers to get around the patents (which VirnetX claimed wasn't enough and was still infringing).
Once that changed there was no point in releasing it as an open standard since it required Apple's servers to operate.
If VirnetX prevails then Skype, Google Hangouts, and everyone else is infringing too and VirnetX will use the precedent to go after them as well. It's a common strategy: go after a couple of people first, establish a win, then use that to leverage settlements out of the remaining players.