.NET Pre-Build
.NET Pre-Build is a cross-platform XML-driven pre-build tool which allows developers to easily generate project or make files for major IDE's and .NET development tools including: Visual Studio .NET 2002 and 2003, SharpDevelop, MonoDevelop, and NAnt.

BuildStudio
Build Studio offers a complete solution for an automated software build process. This is a Windows/.Net application developed in C# and includes both console and GUI options.

BusyBeeBuilder
BusyBeeBuilder provides a powerful, easy-to-use, and extensible .NET build automation tool. It's written with a pipeline architecture that operates plug-ins implementing a simple interface, so it's easy to add your own build steps OR use the several that ship with BusyBee.

CruiseControl.NET
CruiseControl.NET is automated continuous integration server for the .NET platform. It is a C# port of CruiseControl for Java.

DevBuildRunner
DevBuildRunner is being developed as OSI Certified Open Source Software.  It is to provide development teams with simple web based GUI control of their build PC and make selection of build options simpler.

Draco.NET
Draco.NET is a Windows service application designed to facilitate continuous integration. Draco.NET monitors your source code repository, automatically rebuilds your project when changes are detected and then emails you the build result along with a list of changes since the last build. Draco.NET is completely free and includes source released under a BSD-style licence.

Hippo.NET
Hippo.NET is a tool for streamlining the build process of .NET projects in a team envirionment. It provides continuous integration by monitoring the shared Visual SourceSafe database and starting the build process when changes are detected. An important design goal is to provide a nice and easy-to-use user interface, to monitor builds and trigger the build process when needed.

NAnt
NAnt is a free .NET build tool. In theory it is kind of like make without make's wrinkles. In practice it's a lot like Ant.

NAntContrib
NAntContrib is the project for tasks and tools that haven't made it into the main NAnt distribution yet or for whatever reason don't belong there.