From the Croquet welcome page we can read:

http://www.opencroquet.org/index.php/Main_Page

"Croquet is a powerful new open source software development environment 
and software infrastructure for creating and deploying deeply 
collaborative multi-user online applications and metaverses on and 
across multiple operating systems and devices. Derived from Squeak, it 
features a peer-based network architecture that supports communication, 
collaboration, resource sharing, and synchronous computation between 
multiple users on multiple devices."

Interesting part is: "Croquet is derived from Squeak"

Then Croquet license is pretty clear 
http://www.opencroquet.org/index.php/The_Croquet_License

According to this information, Squeak has already been relicensed since 
2002. Or is it a violation of the copyright laws?

Anyway 6 years without a legal suit and even Intel, business angel 
investing money on this technology.

Any though on that...

Hilaire