Honda had VTEC and the whole variable valve timing concept first. When they unleashed the beast at race tracks, they found it to be very efficient and very successful, thus they soon developed it into an everyday vehicle. Furthermore, they also patented the concept for 10+ years I believe and so no one could produce varaiable valve timing until the patent was up. The patent became voided in 2000, thus Toyota and Yamaha used the idea and put better technology into it with the Celica. And now, everyone can have produce variable valve timing.
This is what I have been told by a friend of mine, knows a lot so I believe him.