When it comes to text editors, I’m mostly a jEdit fanboy. But sometimes you want something lighter on system resources–just something to open a Unix formatted README file or do a quick XHTML view/edit. For that, on Windows at least, Notepad++ is a really decent option. It’s based on Scintilla like the SciTE editor, but I like it far better. It has lots of nice, programmer-friendly features, but it starts up in a flash, doesn’t require Java, and is lightweight in general (the installer itself is only 1.8MB), performing nicely even on older systems.
Speaking of new software, I’m writing this with Firefox 2.0, which now has built-in spell checking! Nice!