The first extension took a bit of figuring out how to use I think. It wasn't so easy to just directly do cool things with it. (Although it could do a lot I think)
I bet it was an nightmare to program. I used it in just a standard C++ project and it was often very hard to convince it to do what I wanted it to. And sometimes when I managed to force it, I wasn't entirely sure why what I was doing worked.
