Aptana

Need a free HTML editor?  Head over to http://www.aptana.org/

At first glance, Aptana may seem like a Ruby on Rails editor.  Dig a little deeper and you’ll see that it supports plug-ins.  Keep reading.  Aptana has full HTML support complete with code completion.  Along with HTML, Aptana can be used to edit JavaScript, Adobe Air, PHP, Ajax, Ruby, Perl, and has support for many code libraries including JQuery, Scriptaculous, and Prototype.

Along with these nice tools, Aptana has a built in FTP client to easily and painlessly edit the files on your webspace.  If you want to test your site without uploading it, Aptana has built-in previews using Firefox and IE engines, so you can test your site on both browsers without ever opening them on your computer.

So head over to their website and download Aptana for free.