Intel*. Microsoft don't make semiconductors etc. (their hardware is crap anyway)
core + core 2 are a "spin off" from the original Pentium 4 design, Core i is based on the original P4 as they have can have hyperthreading etc. Core 2 cannot.
Right on the intel not microsoft part, very wrong on where the architectures are from. The Pentium 4 was Netburst Architecture, it had long pipelines so it did pretty good as long as the prediction was good, later ones got hyper threading added on, the Core 2 series is based on the Core Architecture, its not closely related to the pentium 4 and does multiple cores much better. The new Core i series has a couple different architectures but is very different from the pentium 4, all of the Core i's have an integrated memory controller, a much different core layout, and much high IPC rating than any previous processor, the fact that they sport hyper threading doesnt make them similar to the P4's, they just have the second set of registers to do it with to boost their IPCs even higher, hyper threading was not part of the P4 architecture, its a concept all its own and theoretically can be added to any architecture, but it isnt often as it adds more transistors which add more heat and relies on the core being fast enough to have some down time that something else can execute in.