I just download the latest version 1.5.1 and I cant find the Javascript Mode mention in this articel
http://wiki.processing.org/w/JavaScript
What is the status of this feature in the PDE?
Thanks
- rS
1

For clarity, you will need a subversion client (SVN) to download everything and ANT to compile it. But indeed it's not present in 1.5.1. The page you link to also mentions this btw (right at the top):