The Toyota Prius is the world's first production hybrid gas/electric car. The first model was released  in Japan in 1997 and over 35,000 are on the road in Japan today.  The US model has been available to order since Spring of 2000 (when I placed my order).   I received my Prius in August of 2000.

The Prius has both a gas engine (ICE - internal combustion engine) and  a 40-hp electric motor.  It contains a battery pack of 38 NiMH batteries, delivering 228 volts to the motor and alternately, being charged by the motor (run as a generator).

Prius has no transmission in the conventional sense.  It uses a planetary gear system to split and combine the energy to and from the wheels, motor, and engine.

This article, from Marshall Brain's "How Things Work" is quite good.

The first Prius delivered in San Jose was mine.  I'm ready to take it off the lot (after waiting three months).