This site is used as a personal exploration of emerging web technologies.
The calendar is a modified version of Keith Devens's PHP code. The moon phase extensions started with some Perl code that's in the public domain. To correct some errors, I updated this to use the algorithms in Meeus' Astronomical Algorithms, second edition.
The right hand menu which appears on some pages is a floating navigation panel. This is generated on the fly using PHP code, which parses the request uri and figures out which information is being requested. The same routine emits that information into the body of the web page.