There has always been a running joke in the Drupal community that Dries is secretly working on a Java port of Drupal, using an SVN repository. While it makes for a good occasional laugh, there is some truth to that.
Now, Drupal on Caucho has been benchmarked and found to be 3.5 to 4 X faster than Apache and PHP.
This shows that PHP implemented in Java is faster than Zend's engine as an interpreter. These results are without an op-code cache for PHP though, and that needs to be benchmarked for a more comprehensive comparison.
Arto Bendiken (not verified)
Test the Roadsend PHP compilerFri, 2007/06/22 - 09:18
Somebody should test out the Roadsend native-code compiler for PHP, given that it is now open source (since a couple of months back). That should put Java in its place (Roadsend is written in Scheme) ;-)
MoreMon, 2007/09/17 - 12:01
Check also Clustered Drupal through Quercus, Terracotta and Ehcache.
See also my previous post on Life imitates humor: Drupal in Java.
Jonathan (not verified)
Updated link...Fri, 2010/09/17 - 00:23
Just wanted to make sure that link got updated.