I'm looking for free lightweight editors that can be run directly from a flash drive, without any install.
I would like editors that support as many languages as possible, I have notepad++ but I don't particularly care for it.
Edit: Forgot to mention I'm looking for editors for windows.
Check out Programmer’s Notepad , which does have a portable version. I wouldn't say however that is better that notepad++. In fact, I don't think you can get any better than this in the free world.
Although not free, ultraedit has always been a favorite light weight editor for me. I think I definitely got my money's worth with that one.
I swear by notepad2 ,which isn't exactly a code editor, but it has support for syntax highlighting for many text formats, and they just don't come any lighterweight or more portable.
Looking at portableapps.com the only other app I can see that might work for you is Abiword but that's more of a word processor than just a text editor, but might be worth checking out anyway.
Then there is Akelpad, which seems very lightweight: http://akelpad.sourceforge.net/en/index.php
Edit: This is a relevant and researched answer. Can whoever rated this down please explain why in the comments? That would be good netiquette and manners, it doesn't make any sense.
I'm a big fan of vim and Portable GVim makes the goodness of vim portable.
It's got syntax highlighting for more languages that I can name and all kinds of vim goodness.
The choice on portableapps.com is a bit limited: http://portableapps.com/apps/development
There's NVU which looks to be more full-on than notepad++ but personally notepad++ hooked into winscp is my tool of choice for web development at the moment. Anything else gets a bit clunky and unresponsive.
Not sure if it will work from a flash drive but Intype looks promising aswell.
JEdit is a fairly lightweight text editor with all the trimmings. You can dowload loads of plugins. It's written in java, too, so you can use it cross-platform.
Portable version here, thanks to @redsquare for the link.
PSPad is decent, also if you don't mind me asking, what is it exactly you dislike about notepad++, and you do realize with a portable IDE you need the whole works to go with it or you are just carrying around a bloated editor (not matter how lightweight the IDE).
Here is a good site to find all sorts of portable software and here is the editors page.
It sounds like what you're really looking for is a text editor, not an IDE. I have long been a fan of Crimson Editor. There are many great editors for Windows, but I found Crimson Editor to have a really nice interface, and every feature I could want in my text editor, so I've always come back to it for any time I'm not using vim/gvim.
Emacs for Windows should do it. It has been known to run off of CD before. A flash drive should be a cinch compared to that.
To check, I just went and downloaded the latest "bin" version from http://ftp.gnu.org/gnu/emacs/windows/. It unpacked to a 45MB directory. If you can't spare that much space, you are in trouble.
For comparison's sake (and for those of you who prefer another editor) I went through the downloads for everything mentioned here to find the (uncompressed) sizes.
If it were me, I'd try them out in order of editor preference, (from my most to least favorite), then stop with the first one that fits in the space required.
SciTE @ http://www.scintilla.org/SciTEDownload.html
The list of supported languages in very impressive. Includes most features of modern editors - syntax highlighting, code folding, unlimited undo/redo, find/replace with regular expressions, auto indent, etc. It is rock solid - never had it crash or bug out in the 5+ years I've been using it.