n the previous version of Imtech Fields Explorer I have added the possibility of exporting the Content Types and Site Columns to XML. This allows you to configure the content definition for your solution using the user friendly SharePoint Web UI. While it's definitely an improvement comparing to the standard way of typing the complete XML, there are still many situations when you have to access Site Columns programmatically.
This page is being filled with deliciously useful information about the Open Source µ-blogging tool Laconica.
From the ABOUT file: Laconica (pronounced "luh-KAWN-ih-kuh") is a Free and Open Source microblogging platform. It helps people in a community, company or group to exchange short (140 character) messages over the Web. Users can choose which people to "follow" and receive only their friends' or colleagues' status messages. It provides a similar service to sites like Twitter, Jaiku, and Plurk.
Open Source CMS based on Microsoft ASP.Net. Allows Site Editing in Microsoft Word. Integrate any .net based control right out of the box.
Pencil is an animation/drawing software for Mac OS X, Windows, and Linux. It lets you create traditional hand-drawn animation (cartoon) using both bitmap and vector graphics. Pencil is free and open source.