Development Tools

[Michael T. Garrison Stuber]

I don't want to pry, nor am I looking to start any holy wars, but I'm 
curious what people are using for development tools (editors/IDEs etc) as 
they hack GnuCash.

At work (not that they let me touch much source code at work anymore) I
used XEmacs, Vi, and CodeWright, plus proprietary tools from
Digital/Compaq and Sun.  I've also used Oracle's JDeveloper and WebGain's
JavaCafe.
  
I've been using Vi and XEmacs to hack GnuCash, along with TkCVS to stay
synced.  Obviously the Scheme code is impossible to work with without a
decent editor that understands Scheme, and for that XEmacs has been a
lifesaver.  I want to explore some alternatives to XEmacs. 

What do you use?  Do you have any recommendations on tools, things
that you've found make your life easier while working on GnuCash?