Introduction

• the w3c's RDF validator (also contains a link to many RDF test cases).
• IETF's calendar working group: calsch
• http://www.softwarestudio.org/mail-archives/libical/0763.html - interesting email talking about calendar protocols

• RDF calendar task force
• Project Salamander was a project to build a PIM application for handheld computers. It's written in Python and looks like a possible starting point: http://cvs.handhelds.org/cgi-bin/viewcvs.cgi/salamander/ , http://www.xfree86.org/~keithp/xconf2001/salamander.pdf . The project looks dead now (replaced with another project called GPE, written in C) but the code might be better than starting from scratch.
• ToDo Manager looks like another good baseline. It's written in Python, and unlike Salamander it seems to be under active development. http://todo-manager.sourceforge.net/