I thought that the current version of the Prius was the 3rd one, but discovered today that it is in fact the 4th iteration of the Prius model. More information in Wikipedia here.
The first model (named internally NHW10) was sold only in Japan from 1997 to 2001. This means that the Prius selling today is the 4th model (named ZVW30) and has an history of at least 13 years. If you add to that the development cycle of the first Prius, started in 1994, the Prius hybrid concept is established in Toyota since 15 years.
Main differences between the models can be found here.
The domain name of this blog will remain prius3.wordpress.com until I figure out a way to change it to prius4… 
