jEdit

I have been looking for a multi-platform program editor since I bought a Mac. I was using Kate, and really like it. But then I started using jEdit. Uau! Super powerful, light, easy to install. Kate is buggy on Windows and a nightmare to install on a Mac. To install a simple text editor, you need to install Xcode developer tools (~2 GB), Fink (another couple of GB and hours for installing) and then KDE. That was when I gave up, after more than an hour of text running down the Terminal window.

Just another thing. The rendering of text without any smoothing can be quite awful. Go to Utilities/Global options/Text area and chose the best combination of smoothing and font metrics for your monitor. Play a bit with the highlighting colors and you're good to go!

When I do software development I'm typically either in Netbeans (for JVM stuff) or I'm in jEdit. I'm conversant with a bunch of other text editors (I'm mostly editor-agnostic, you see, although Emacs never gets even a keystroke out of me) including Notepad++, Gedit, Vim and a few others, but jEdit is the one I use most, partially because I can carry it with me on my USB stick and it will run on pretty much any platform I stick it in. (I carry my own JVMs as well, you see.)

Currently using sublime as my main text editor. After switching to linux, had some problems with text encoding which was easily fixed by using jEdit. Doesn't replace Sublime but is definitely a tool I will always keep.

A great Java-based text editor, but relatively inactive community.