When I used to write code I used emacs on Unix and notepad++ on Windows. The only time I used an IDE was when I started using Visual Studio in the late 90's when my company started to transition the bespoke software to Windows from Unix. All my UBB and vbulletin hacks where done with notepad++.
I also no longer use Windows as my everyday OS, switched to OSX full time, so other then firing up a VM to install notepad++ what do you recommend to use for development?