We just featured SCal, and now we have a MooTools Calendar component created by Aeron Glemann.
I have tried to make Calendar as semantic as possible–with proper usage of CAPTION, THEAD, TBODY, TH and TD elements–and lots of CSS styling hooks. View the Calendar stylesheet for examples of the CSS; see the Styling Your Calendar section in the Manual for references to the XHTML.
You create the beast via:
And you end up with some pretty stuff:
opensource: del.icio.us tag/opensource
calendar
JavaScript
component
opensource
Prototype
Date
Time