Nice. The 2-3x improvement is about the same that I've seen in preliminary tests with HHVM on a JSON API in ZF2. There are still many extensions that are not po

Nice. The 2-3x improvement is about the same that I've seen in preliminary tests with HHVM on a JSON API in ZF2. There are still many extensions that are not ported at all, something Box didn't run into but I have. These are lesser known extensions, but they can throw a wrench in the migration works. I would definitely check the status of all extensions and as the article mentions, test their code most extensively. My biggest problem still is getting xDebug working with HHVM, something that after a few days of trying I have given up on once again (as of a couple of months ago). Unfortunately, a procedural or OOP language without a proper debugger (hphpd doesn't count) is pretty useless for real-word development. I know the HHVM team is constantly working on improving the ecosystem, so hopefully at some point, we'll have a real debugger that runs without crashing. Once that happens, I can definitely see rewriting the sections of the app that use extensions not yet ported to get the app ready for deployment on HHVM. Right now, the only reason we haven't done so is that we do want to compare both HHVM and PHP7 to see which one will yield the best performance.