Kris Kohler has posted an article on Kotaku about the PlayStation Classic, where he says:
(A listing of licenses for open-source software accessible in the PlayStation Classic’s menu said that it uses the open-source PlayStation emulator PCSX ReARMed.)
I was wondering if this was and is known by the developers.
Well, it’s known now if not before. It’s mostly the work of notaz and exophase, but I haven’t heard anything from them about it either way.
Since it’s GPL, as long as they provide source code with any changes (spoiler: there probably aren’t any changes), Sony’s probably okay whether they talked to them about it beforehand or not (IANAL, and this is a prerelease product, of course, so it’s all supposition right now).
At this point, we don’t know if they’re using a standalone build or a libretro build with their own frontend (either is possible).