JSEditor is gone, but not really

JSEditor disappeared from Adobe Labs and is not only available inside of Flex Builder, but it turns out that the install site is still there and is actually the same version included in Flex Builder. You can add the install site: http://download.macromedia.com/pub/labs/jseclipse/autoinstall/site.xml and it will install. You will probably need to set JSEditor to be your editor for *.js