Windows Whistler

Windows Whistler is an operating system developed and compiled by Microsoft. It is the beta OS and codename for Windows XP.

Pre-Luna
This describes the development and builds before Luna was implemented.

In the late 90s, development at Microsoft wanted to create two separate projects known as Neptune and Odyssey, both of them running on the NT kernel. Neptune was for consumers and Odyssey for enterprise. These two projects would later form into one, unified project called Whistler in January, 2000.