has been around for a good while and has established itself as the premier Content Management System on the Web.
The DotNetNuke system is based in the Microsoft ".NET" architecture and has a rich and extensible library of "methods" that may bee called upon.
DotNetNuke controls are identical to a .NET/ASP custom user control. I use this construct extensively in all Web oriented work as it makes the new/custom work easier to import into a client's framework.
This also allows any of my controls to be usable either on the web as a stand alone component, or incorporated into a DNN site.