I noticed Charles Nutter (one of the JRuby developers) mentioning that the fork() method in JRuby will most not likely be supported:
We would strongly prefer to avoid any implementation that requires fork, since we can’t really support fork in JRuby.
While I can understand the difficulties in the Java VM giving lots of hell trying to handle something like fork() I feel it’s a shame since it means if you use fork and quite a few process related calls in Ruby it will not be portable in JRuby. For a sysadmin, handling processes is one of their jobs so personally, I hope they can come up with some way to handle it somehow. But JRuby’s strengths might not be in a scripting language for sys admins but providing a way to integrate rails with the monster that is J2EE. How cool would it be to develop a rails application all in the context of a java web application that you can just deploy right into a Java application server? I think this could be JRuby’s little nitch (besides being an integration tool for java devs)
