In one of my previous posts I wrote about clustering solutions for Ruby. One of them was MagLev, based on Gemstone's Smalltalk virtual machine, the second one was based on Terracotta. The latter solution seems more appealing, since Terracotta is open source, and lets you do some own experiments (like this, or this, or even this). Unfortunately, all solutions I have seen so far (including my own) for JVM based languages other than Java depended on a special library that interfaced Terracotta through com.tc.object.bytecode.ManagerUtil class instances, and were not transparent to the programmer. Until now.
Recently, Fabio Kung took a step further and patched JRuby to behave like MagLev, transparently sharing objects across multiple JRuby runtimes. It seems that MagLev got a strong competitor before it even managed to hit the market. Have a look at the demo, it looks equally impressive to what Avi Bryant from Gemstone showed at RailsConf 2008.