YAF.NET - C# ASP.NET Forum
Fluent migrations framework for .NET
Blogifier is an open-source publishing platform Written in ASP.NET
A Free, complete, enterprise grade, open source exam management system
An editor for structured documents
An algebra editor
ASP.NET MVC Based Portal CMS System to Create an Instant Website
Usercontrol ASP WYSIYG Editor
NS-ORG IDE for DOT NET Programming
LaTeX, AscciMath and MathML editor developed in Javascript and HTML
WYSIWYG html editor for .NET (C#, VB.NET)
Wiki .net is a simple and open source wiki engine running on Asp.Net
cross platform latex-to-bitmap-to-clipboard gui
ASP.NET Framework for Open Source Libraries
FCKeditor Editor
ogeditor is Web-based simple CMS with powerful WYSIWYG/Script editor