Shawn Willett, analyst at Current Analysis, described Sun's move as "pretty radical."

"I guess they will recoup the license revenue through services and of course underlying hardware," Willett said in an e-mail.

They are not really detailing new services and support programs around this, however, which they need to do, he added.

"This will have the most effect on integration and portal markets, where there is not really good open source products on the market. It will be interesting to see if competitors in this space will respond and how," Willett said.

Sun made Solaris available via open source in June.