[http://www.activestate.com/Products/Komodo/ Komodo] from ActiveState is a rich ["IDE"] for Perl, Python, PHP, Ruby and Tcl. It offers many integrated tools (i.e. code completion, code debugger, regular expressions toolkit, etc).
ActiveState also introduced a free Komodo-based editor, called Komodo Edit, which is less functional but available at no cost.
The page titled "IntegratedDevelopmentEnvironments" includes several reviews of Komodo. [http://www.unixreview.com/documents/s=10125/ur0704b/ Here], in April 2007, is one of Komodo 4.