http://www.codeplex.com/CKS - Community Kit for Sharepoint - A set of best practices, templates, Web Parts, tools, and source code that enables practically anyone to create a community website based on SharePoint technology for practically any group of people with a common interest.
http://www.codeplex.com/SLK - SharePoint Learning Kit - a SCORM 2004 certified e-learning delivery and tracking application built as a Windows SharePoint Services 3.0 solution. It works with either Windows SharePoint Services 3.0 or Microsoft Office SharePoint Server 2007, and has the following core features: (1) Supports SCORM 1.2, SCORM 2004, and Class Server content, allowing users to store and manage this content in SharePoint document libraries. (2) Supports learner-centric and instructor-led (assigned) workflows. (3) Allows assignment, tracking and grading of both e-learning and non-e-learning content.
http://www.codeplex.com/stsdev - STSDEV: Simple Tools for SharePoint 2007 Development - A SharePoint developer's utility designed to quickly transform your ideas into real-world components that you can deploy into a staging or production Web farm with confidence.
http://www.codeplex.com/ChartPart - ChartPart for SharePoint is a web part for Microsoft SharePoint Services 3.0 or Microsoft Office SharePoint Server 2007 which generates charts from SharePoint lists. The ChartPart is free to use for everyone, as long as you follow the License, who would like to "light" up their SharePoint installation with some nice graphs and charts.
http://www.codeplex.com/iLoveSharePoint - PowerEventReceivers, PowerWebPart (supports AJAX and JQuery, execute PowerShell Script in a WebPart, render HTML and write ASP.NET code with PowerShell syntax), PowerActivity (execute PowerShell Scripts in a SharePoint Designer Action), Lookup Field with Picker (Single- and multi-Selection Mode, searching, search operators, select the fields you would like to search for, supports default values...), PowerShell Scripts V1.3, List without Title Column (you often doesn't need the title field but unfortnuately the context menu is attached to the title field so you're forced to use it anyway. Tha's over! Just try the List without Title Column. The context menu is attached to the ID of the List Item), User WebService (useful to switch views depending on the current user's SharePoint groups in Infopath; actually the WebService has only one method: GetUserGroupsFromCurrentUser ... a build-in SharePoint WebService which does the same?! Yes, but the built-in service doesn't work with Infopath 2007), Codename SPAC - SharePoint Assembly Cache (realized with SharePoint and WCF), and much much more.
http://www.codeplex.com/sptdatapop - SharePoint 2007 Test Data Population Tool - The SharePoint 2007 Test Data Population Tool (WSSDW.exe) is a capacity planning and performance testing tool that populates data for testing SharePoint deployments. The SharePoint 2007 Test Data Population Tool is available as a command-line executable program that extracts information about how to populate the server from an XML configuration file, and calls Microsoft .NET assembly: WSSDWLib.dll. Use this tool to populate test data for SharePoint capacity planning. Also included are some sample test scripts that can be used for performance and load testing SharePoint and Excel Services with the test data.
http://www.codeplex.com/pks - Podcasting Kit for SharePoint - Listen and watch audio/video podcasts, anywhere on your PC or mobile device (Zune, SmartPhone, or any podcasting device); Share content by producing your own audio/video podcasts and publish them on PKS on your own; Connect and engage with podcasters via your integrated instant messaging program; Find the most relevant content using the five star rating system, tag cloud, search engine and provide your feedback via comments; Get automatic podcast updates by subscribing to RSS feeds fully compatible with Zune and other podcasting devices; Simple RSS feed based on a defined podcast series; Simple RSS feed based on a person; Dynamic RSS feed based on search results (will be implemented later in 2009); Play podcasts in real-time using Microsoft® Silverlight™ and progressive playback; Retrieve instant ROI and metrics with the ability to track the number of podcasts downloaded and/or viewed, instant feedback via rating system and comments, and subscribers via the RSS feed; Access the richness of SharePoint to extend the solution: workflows, community sub-sites, access rights, editorial and more; Customize your own PKS User Experience