Variocam was developed for the 968 in 1991. It used a timing chain to vary the phase angle of the camshaft, thus providing 3-stage variable valve timing. The 996 and Boxster use a similar system. This design is actually inferior to the hydraulic actuator used by other car makers (such as VTEC in your original question) since it doesn’t allow as much variation to phase angle.
I believe what MNBoxster refers to as the "2nd Gen Variocam" is known in Porsche-speak as Variocam Plus which was introduced with the 996 - 911 Turbo and is standard on the 997. "Plus" uses the hydraulic actuator instead of a timing-chain and provides continuous (infinite) variable valve timing. More importantly, as 986Jim notes, the "Plus" adds variable valve lift.
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