The early-access release of the NetBeans Ruby Pack is comprised of a plug-in to the open-source NetBeans development environment supporting Ruby and JRuby, which is a Java implementation of Ruby that runs on the Java Virtual Machine. NetBeans has been centered on Java but is being extended to Ruby.

Ruby developers typically have not been using IDEs, Sun officials said. But Sun's announcement "really gives you a much more productive environment than you've had for Ruby before," said Tor Norbye, a Sun senior staff engineer.

Sun has taken notice of the popularity of Ruby. "It's offered a new way of looking at development: more agile, more fun in a lot of ways," said Charles Nutter, also a senior staff engineer at Sun. He and Thomas Enebo are the core developers of JRuby; both began working at Sun in September.

By accommodating Ruby, Sun is branching out from its Java mindset, said James Governor, principal analyst at RedMonk.

"If you just look at this overall, there are some sacred cows being slaughtered here," Governor said. "There is a real change in Sun's thinking, and it really does [appear] that the Java permafrost is beginning to thaw," with Sun supporting scripting languages like Ruby, he said.