Jash is no longer maintained. There are many mature, full-featured JavaScript consoles to choose from. Jash was created during a time when IE6 debugging was almost impossible.
Jash is a JavaScript and CSS shell. It allows you to run arbitratry JavaScript or CSS on a web page. The shell is implemented as a floating, resizable, repositionable DHTML window in the current HTML page. Jash is invoked using a bookmarklet.
Change the script src in the bookmarklet below so that it points to your hosted path for Jash.
javascript:(function(){document.body.appendChild(document.createElement('script')).src='path/to/Jash.js';})();
The only prerequisite to building Jash is ruby >= 1.9.x.
rake build