Namusyaka-bookmarklets is a project mainly written in JavaScript, it's free.
bookmarklets.
git clone git://github.com/namusyaka/namusyaka-bookmarklets
My bookmarklets.
As external file
javascript:(function(){document.getElementsByTagName('head')[0].appendChild( document.createElement('script').src = 'File URL' )})()
As pure script
javascript:pure js source.
namusyaka
MIT License