"As promised, Microsoft delivered an interim build of Windows Vista–build 5219–to attendees of the Professional Developers Conference (PDC 2005) in mid-September 2005. That build, which later went out to technical beta testers and MSDN subscribers, represents an interesting but incomplete look at the progress Microsoft has made since July’s Beta 1 release. Microsoft is also referring to this build as Windows Vista Community Technical Preview (CTP 1), or as the September 2005 CTP. That notation is important: There will be an October 2005 CTP as well, and likely a November CTP. The goal is for monthly builds from here on out, and public monthly builds beginning with Beta 2 in December. Now that’s transparency."
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