[UPDATE: check out the official Open Komodo blog post from ActiveState] 

Got an advance briefing about Open Komodo (initially a portion of Komodo Edit combined with other open source goodies) which is an open source client side (JavaScript, HTML, CSS) web application development platform from our friends at ActiveState and Mozilla. Add debugging and PHP support (hopefully soon, LazyWeb ?!?) and you have a killer open source Drupal development environment as well as one for XUL based Rich Internet Apps and CSS/HTML/JavaScript Web Apps (e.g. iPhone apps). Can't wait to try it and see how it evolves!