I'm not sure if many people know about this text-editor?
jEdit was kinda big in 2004, but now, Notepad++ seems to have taken the lead(on Windows) Many of the plugins haven't been updated since 2003 and the overal layout and usage is confusing...
I'm sure jEdit has many nifty features, but I'll be damned if I can find out where to find them and how to use them. Reading that manual is a fulltime job on it's own.
I've been using jEdit for a few years now, mainly on windows, but also on Ubuntu.
I use it for: SQL, awk, batch files, html, xml, javascript...
Just about everything except .NET stuff (for which I use Visual Studio).
I love it.
I use jEdit because it has the right balance for me of ease of setting up vs. features and customisability. For me, no other editor strikes quite as good a balance.
In the past I did take a look at Notepad++, but that was a while ago, and it didn't have a nice way to define your own syntax highlighting, which is important for me. I also paid for Textmate and UltraEdit at different times (both very good), but in the end, jEdit comes out on top for me.
I also used Eclipse for a year or so. It's fantastic, and it'll do anything you want, but you have to be really into Eclipse to get the most out of it.