Seems if you want homebrew/unsigned code on your ps vita, a webkit exploit has been found but only on 3.18 (and below?). From Wololo.net: http://wololo.net/2014/09/22/native-vita-hacking-whats-the-situation-so-far-part-2/ "Hey everyone Shortly ago Acid_Snake posted about the state of the Vita scene, calling to the forefront yifan’s recommendations to go after webkit. Well you may all be in for some good news. Around July of this year, I returned to the scene after a while’s absence and decided to dedicate myself to webkit. I founded a new team dedicated solely to hacking the native side of the vita, codenamed Project Mayhem and eventually named “team mayh3m.” Over a period of 3 months we have been able to get nearly all the way through the process of exploiting webkit. The purpose of this post is to encourage you not to update to 3.20 if you desire to work with webkit, as well as to bring other developers up to speed in terms of where we are in the exploiting process."