One of the key features of Chandler, OSAF's open source personal information manager (PIM), is to provide robust and interoperable sharing of data between users. The networking part of sharing leverages is a protocol library, named "zanshin", that heavily leverages existing python technologies such as Twisted, the event-driven networking framework. To be able to share interoperably, we have adopted established IETF standards like ICalendar, HTTP and WebDAV, as well as the emerging CalDAV standard.

The goal of this presentation and paper is to present a case study in implementing interoperable, standards-based network clients in Python. I plan to discuss some of the design and implementation trade-offs we've made in Chandler, focusing mainly on the work done for sharing calendars, but touching also on other areas of personal information management, such as email.