Well, he says he's developing "an extension for php", so I'm assuming that means he intends to create his own game-building toolkit/framework.
If that's correct, I'd say the best place to start is by building at least two or three complete, working games, so that you can see for yourself both what's needed and which pieces will be useful in multiple games vs. those which are specific to only a single game. Pulling out the common pieces and abstracting them is generally the best way to build a toolkit.