The Darwin Calendar Server is a standards-compliant server that allows multiple users to collaboratively share calendaring information. It provides a shared location on the network to store schedules, and allows users to send each other and manage invitations. In order to provide interoperability with multiple calendaring clients, the server implements the CalDAV protocol, which is an extension of WebDAV, which is in turn an extension of HTTP.
The POP and IMAP troubleshooter serves to diagnose and solve connection problems from client machines to email services. It reads the client configuration files (Outlook, Windows Mail, Thunderbird, etc.), checks the individual settings, and then attempts to create POP, IMAP, and SMTP connections using these settings. The troubleshooter is coded in C++ using the Qt environment. It can be used generically, or can be customized for the demands of a particular email service.
Chandler is a standards-based "Note-to-Self Organizer" designed for personal and small-group task management and calendaring. It consists of a desktop application and Chandler Hub, a free sharing service and Web application. You can also download and run your own Chandler Server.
OpenDMTP (Open Device Monitoring and Tracking Protocol) is a highly configurable and extensible protocol for communicating with mobile devices over high-latency/low-bandwidth networks. The protocol is particularly geared towards the transmission of GPS base location information and includes a full-featured reference implementation showcasing its capabilities.