Wonderful online Javascript editor Mozilla Skywriter (since the end of 2008 was known as Mozilla Bespin, renamed in October 2010) became part of the integrated development environment Cloud9 IDE . This is an environment sharpened specifically on JavaScript, which works through the browser and is positioned as an alternative to offline IDE like Eclipse. Now in beta testing.
Mozilla Skywriter is now merged with ACE's Javascript editor (Ajax.org Cloud9 Editor) . It is distributed under three MPL / LGPL / GPL licenses, which now apply to Skywriter.