iCal4j is a Java API that provides support for the iCalendar specification as defined in RFC2445. This support includes a Parser, Object Model and Generator for iCalendar data streams.
GCALDaemon is an OS-independent Java program that offers two-way synchronization between Google Calendar and various iCalendar compatible calendar applications. GCALDaemon is primarily designed as a calendar synchronizer but it can also be used as a Gmail