cd ~/Library/Application Support/TextMate/Bundles
git clone git://github.com/subtleGradient/javascript-tools.tmbundle.git
In Textmate, Bundles > Bundle Editor > Reload bundles
Now open a Javascript file and to Control-Shift V and choose “JSLint”
Also install Node.js
https://github.com/joyent/node/wiki/Installation
(Mac user can install using this package: https://sites.google.com/site/nodejsmacosx/)