A recent news article mentioned PHP implemented in Java and how it's fast and how Drupal runs. We began to discuss this in #drupal and found an earlier blog entry which also mentions the same. The latter also raises the concept of porting Drupal partially to Java.
Things went downhill from that point in the channel. redLED thinks that would lead to "drupal becoming a concept, like 'on rails' :p and gets ported to *".