Proto.Menu is a simple and lightweight prototype-based solution for context menu functionality on your page. It is about 2 KB ( 1.5 KB Minified). It is Unobstrusive which plays nice with Javascript turned off and uses its own namespace, so it won’t messed up with your codes. The menu styling can be easily defined in external CSS. It is also a Full A-Graded browsers support (Opera is supported through Ctrl + Left Click). It looks very tidy and suitable for web applications with context menu.

Requirements: Firefox 1.5+, Internet Explorer 6+, Safari 3+, Opera 9+, Netscape Navigator 9+
Demo: http://yura.thinkweb2.com/scripting/contextMenu/
License: License Free