Well, it's a 7 years old script, and from the publisher site, I see that there are no newer version/update since 2005. Not really a bad idea if you wanna play around and explore the possibility, maybe even to study how it works and create something similar. The only main concern is that the "store" script required register_globals to be on, which encourage url injection thus might raise some security issue. But well, 7 years back this might not be a big concern anyway.

I don't know how it got a near 6 rating, but I would definitely give it a -1. The installers for the portal and store do not do a thing, enter the information, and it says missing data and sends you back to the beginning.