The Table of Equivalents is useful for finding Open Source equivalents for common Windows applications.

Software Freedom Day is an annual event held in August.

OSS Chicago is an example of a well-designed community resource.

The Open Source Applications Foundation is a non-profit foundation with a mission to create and gain wide adoption of Open Source application software.

The LinuxFund is a public charity that funds Open Source software development.

The The FreeBSD Foundation is a non-profit organization dedicated to supporting the FreeBSD Project.

Palm Open Source has everything Open Source for the PalmOS.

Open Source E-Commerce Solutions provides resources for creating Open Source e-commerce solutions.

dwheeler.com contains several papers on evaulating and promoting Open Source software.