: Builds are categorized by "Milestones" (M1 through M7) and "Beta" phases, documenting the shift from the original vision to the post-reset Vista era.
: A communication framework that became the Windows Communication Foundation (WCF). : Builds are categorized by "Milestones" (M1 through
: A graphics engine that became the Windows Presentation Foundation (WPF). : Builds are categorized by "Milestones" (M1 through
However, the code became so unstable and unmanageable that Microsoft scrapped years of work in 2004, resetting development to use the Windows Server 2003 codebase as a stable foundation. This revised project eventually launched in late 2006 as . Legacy and Build Collections : Builds are categorized by "Milestones" (M1 through