Frequently I'm brainstormed with programming ideas that I would like to directly code. More or less like "Wow, that algorithm will rock! I need to write it now!".

For this kind of "impulse" to write, I use http://www.jarte.com/ that is a cool portable text editor. If I'm near a cybecafe or a friend computer, I just plug the usb pen drive and start to write...

So, I would like: 1) a portable minimalist IDE 2) with minimal OS requirement (ie.: I want run from XP, Vista, etc...) 3) any modern language (I can learn a new language if needed. I just want write/test the algoritm) 4) Syntax Highlight/intellisense is good, but not required 5) Free

Is there something like this?