Name of JavaScript in-browser editor

I remember using a JavaScript in-browser editor a while back but cant remember the website despite doing numerous Google searches.

The website in question has two large grey buttons at the top left named on the lines of "code" and "preview" and the rest of the page is used to write开发者_开发问答/view code.

It sounds like you're thinking of JSBin: http://jsbin.com/

There's also another you should check out though, jsFiddle: http://jsfiddle.net/

For year 2013, developers should also look at Eclipse Orion and c9.io Cloud IDE.

Be aware, however, that if your internet connection is slow, using such tools is not pleasant. You should install them locally, in LAN or have Desktop application.