I'm trying Aptana3 but I don't find an essential feature :
Remove trailing whitespaces/empty lines on save.
This is now possible.
Preferences -> Aptana Studio -> Editors
Check "Remove trailing whitespace characters"
Not possible with Aptana 3.1. See
But since Aptana is (was?) based on Eclipse, you can also try
Works fine with this Eclipse plugin http://andrei.gmxhome.de/anyedit/ Tested with Aptana 3.0.7