ASP.NET Library of C# Code
BlogEngine.net open source ASP.NET Blogging Software
BlogEngine.NET is an ASP.NET 2.0 that's very easy to setup and customize. It comes with features expected from a modern blog engine plus AJAX comments, social bookmarks, OpenSearch support, XFN tags, AJAX, FOAF, SIOC, APML, Gravatars, coComments, tag cloud, Google sitemap and other so called Web 2.0 features.
If you're a Git User (that's the Distributed Version Control Sysytem developed by Linux Torvalds of Linux fame) on Windows, this provides a way to manage your own repositories. Bonobo Git Server for Windows is a web application you can install on your IIS. It provides you an easy management tool and access to your git repositories, with secure and anonymous access to git repositories,user friendly web interface, user and team based repository access an browse acces to the repositories.
BugNET - ASP.NET 2.0 with multiple database support
BugNET is an issue tracking and project issue management solution built using the ASP.NET web application framework. Email notifications, reporting and per project configuration of fields and values allows efficient management of bugs, feature requests, and other issues for projects of any scale.
BugTracker.NET - Open Source ASP.NET bg tracker
BugTracker.NET is a free, open-source, web-based bug tracker or customer support issue tracker written using ASP.NET, C#, and Microsoft SQL Server (or its free cousin, SQL Server Express). It is in daily use by thousands of development and customer support teams around the world.
Comm100 Forum Software Open Source
An impressive forum web application that can be hosted on your own server and needs SQL Server and IIS or on Comm100s (100% free). It's licensed under the liberal MS-RL license. Comm100 supports unlimited categories and forums with sticky posts, private messaging, searching and user control panels.
DoLoTo - Download Time Optimization for Web 2.0 Apps
Doloto is an AJAX application optimization tool, useful for large and complex Web 2.0 applications that have a lot of code, such as Bing Maps, Hotmail, etc. It analyzes AJAX application workloads and performs code splitting of large Web 2.0 applications. After processing an application will only transfer the code needed for initialization. The rest comes later.
Facebook Developer toolkit
This is the new version which tracks Facebook's revamping of their site and includes support for Silverlight, ASP.NET MVC as well as ASP.NET, WPF and new FBML. It simplifies writing Facebook Applications in C#.
Master Page and css for Multiflex 3 Website Template
Multiflex 3 is a free website design from http://www.1234.info/webtemplates. This is a conversion of it to ASP.NET 3.5 Master Pages with css files. It was created by the Cplus guide.
A rival to Wordpress, Funnelweb is written using ASP.NET MVC 3, Nhibernate and the Razor View engine. It's a sophisticated theme driven blogging platform.
MVC 2.0 Music Store Example
This is an example of using many of the features of ASP.NET MVC including some of the MVC 2.0 Features. There's an 80 page PDF that explain the code and covers Master Pages, LINQ extensions, using the Entity Frame Work, Lambda expressions, Models, View and Controllers (the M, V and C in MVC), HTML helpers, Ajax.ActionLinks and use of jQuery.
ScrewTurn Wiki Software - GPL Licensed
ScrewTurn Wiki is extendible and customizable with plugins and themes. It can store data using flat files or in SQL Server. it includes NameSpaces (for partitioning sections of the Wiki), a WYSIWYG Editor, unlimited Page Attachments per page, an Image Editor and an advanced permissions systems with optional article moderation.
SignalR - Asynchronous Library for real-time, multi-user web apps.
The JobPing ASP.NET MVC 2 URL Shortener
A URL shortener like bit.ly, goo.gl or tinyurl.com, this is a single page ASP.NET MVC 2 project that uses LINQ. It's used in their website jobping.com
Umbraco Content Management System
Umbraco is an open source CMS (Content Management System) and can best be described as the ASP.NET equivalent of the PHP open source Joomla CMS. Umbraco lets you define a content driven website with users, writers, editors and fine grained permissions to create, edit and publish a range of documents to make a website that's infinitely configurable and styleable. Also see Umbraco User's guide book review.
WikiPlex a .NET Wiki
WikiPlex is a regular expression based wiki engine that lets developers add a wiki experience into a .NET application with little effort. Built and used by the CodePlex team, WikiPlex has been thuroughly tested in real-world scenarios!
Windows Azure Toolkit for Social Games
YetAnotherForum.NET C# forum Software
YAF is ASP.NET forum software that support unlimited number of boards forums, categories, and messages, user groups, and ranks. It provides multilingual support and Unicode (UTF-8) encoding. Layout is by template-based design.