DotNetNuke evolved from a project called the IBuySpyWorkshop (IBSW.)  It was renamed to DotNetNuke to avoid confusion with Microsoft’s portal starter kit, known as IBuySpy Portal.  The new name was chosen to reflect the applications .NET (DOTNET) framework, and coupled with the term “nuke” (due to *nuke’s inherent, industry-recognized inclusion in several existing open source portal initiatives.)