The following applications and tools are available as freeware and open source products. Please note that support for these products can only be given on a best efford base.
Domino iCalendar Support for Calendar Entries (Freeware/Open Source)
The iCalendar support for IBM Domino publishes all calendar entries from the user in the iCalendar feed format. This allows the user to show the calendar entries on platforms which are not supported by IBM Traveler (OS X, Outlook, etc.) or in environments where it is not desired to locally synchronize the calendar.
Domino iCalendar Support for Contact Birthdays (Freeware/Open Source)
The iCalendar birthday support for IBM Domino publishes the contact birthdays in the iCalendar format. This allows the user to show the birthdays as calendar events on any platform which supports the iCalendar format (iOS, OS X, Outlook, etc.)
StatInspector (Freeware/Open Source)
The Domino Server Statistic Inspector (StatInspector) is a small server Java addin, which monitors the server statistics based on user definable probe documents and creates alert documents when needed.
POP3 Collect (Freeware/Open Source)
The POP3 Collect add-in task for IBM Domino reads messages from one or more POP3 servers and sends them to the Domino server or any other SMTP Server (Exchange, Postfix, Sendmail, etc).
JAddin (Freeware/Open Source)
The JAddin framework is a very thin and convenient layer between the Domino RunJava task and your Java application code. It greatly helps you to create Java tasks for Domino by freeing you to learn all the Domino addin specifics such as message queue handling, subthread creation, Domino resource cleanup, etc.