A JavaScript site search engine. It works with any browser that supports JavaScript 1.3 and at least partially supports the W3C DOM Level 1. [Open source, GPL]
Zapatec Javascript Menu is a search engine friendly cross browser compatible menu. Zapatec Javascript Calendar is a cross browser compatible calendar. Zapatec Javascript Tree is a cross browser search engine friendly way to display information.
Add javascript Popups Announcements to website. Popup content can be easily changed by the website owner - from the Popup itself. Requires registration (Free) and easy install code.