Sorry if I voted twice (feeble memory ), but I use Nedit since it's a feature rich, plain text editor. It runs on nearly every platform, has good mouse support, syntax highlighting, search and replace, runs or gets the result of CLI commands, recent document list,..
Give it a go, if you have not done so recently.

< poop! page 2. I need more coffee. subtract 1 vote from nedit results >

I discovered something called "Kate" that came with my Suse Linux installation.

It is very close to what I am used to seeing with EditPlus (I have used EditPlus on Windows for 6 years and think it is excellent - How can you use EditPlus it on Linux, besides resorting to "wine"?) Kate supports syntax highlighting, key sequences that allow convenient navigation, copying/pasting and deletion, directory browsing and more. I am really not sure, though, what OS it comes packaged with, and whether it is Open Source (I just haven't had the time to investigate!) If anyone knows these answers, please let me know too (and don't forget the EditPlus question!)

The software will not allow you to vote twice. Try it and see. When you posted your first post, there was no nedit option. After praze also indicated a preference for nedit, I added the nedit option as I mention in a post on page 2. nedit has received two votes one from you and one from praze.

Emacs is grate
but I like VIM more

vim and sometimes mcedit