Shouldn't Joomla team have mentioned "Based on Mambo Open Source Software" somewhere then ? or restart from scratch without ripping all the code into their new Open Source project ?

Actually, they've done just that and they announced their intention to fork the code before it was done.

Vtiger did indeed look at the SugarCrm (mentionning it explicitly by the way along with other OS projects... that didn't complain... wonder why) and turned it into a great open project.

They just looked at the code, eh?

I have this idea for a movie: There's going to be a kid with a lightsword who runs around fighting bad guys wearing white armor suits but then comes up against the head bad guy in a black suit wielding another lightsword. Of course, in the end the kid wins out because the black suited guy is really his father and has a change of heart at the end. The movie will finish with the kid sitting around with his friends one of which happens to be his sister and everything is right in the end.

I'm going to name it VWars... anyone interested?