- NLog Logging and Auditing – http://nlog-project.org/
- NHibernate – ORM – http://nhforge.org/Default.aspx
- Spring.Net – Aspect Oriented Programming (AOP) DI/IoC – http://www.springframework.net/
- NUnit – Unit Testing –http://www.nunit.org/
- Microsoft Enterprise Library – Data Access, Logging/Auditing, Caching, Security, Validation, Exception Handling etc. http://msdn.microsoft.com/library/cc467894.aspx
- NetSqlAzman – authorization manager for .Net http://nik.pevik.com/authorization-store-for-net-net-sql-authorization-manager-netsqlazman/
- Castle/Windsor (MicroKernel/Windsor) http://www.castleproject.org/castle/download.html
- DotNetNuke — CMS http://www.dotnetnuke.com/
- Mono — .NET 4 OsX/Linux – http://www.mono-project.com/Main_Page
- JQuery/Dojo/GWT —> Javascript Frameworks
- myBatis.NET – http://mybatis.org/dotnet.html
- NAnt –> building utility http://nant.sourceforge.net/
- CruiseControl.NET automated building tool http://confluence.public.thoughtworks.org/display/CCNET/What+is+CruiseControl.NET