Komodo Edit is a Free Open Source Editor for Perl, Python, Tcl, PHP, Ruby & Javascript. I should check it out, as TextWrangler doesn't have folding, BBEdit is too expensive in my opinion, and TextMate has too modest Python folding support. And if this thing runs well across different systems, I would finally have a uniform GUI editor again (yes, I know, vim is available everywhere, but the GUI version just doesn't appeal to me).
Update: uh, hello, ActiveState? I understand that you want to sell your "cheap" IDE (special offer! Only $330), but at least Komodo Edit deserved the source outline, right?