It used a company blog post to announce that the decision came following "feedback from its partners" (see: angry complaints from developers), adding that the three builds will be available from today. The Enterprise RTM version for businesses will be available "later this month".
The company is also providing MSDN and TechNet subscribers access to the Release Candidate of Visual Studio 2013.
Microsoft chief evangelist Steve Guggenheimer wrote: "We've listened, we value your partnership, and we are adjusting based on your feedback. As we refine our delivery schedules for a more rapid release cadence, we are working on the best way to support early releases to the various audiences within our ecosystem."
Had Redmond stuck to its guns, developers would have had to wait for the consumer release of Windows 8.1 to land on October 17, which would have made paying for Microsoft subscriptions to get early access rather pointless.
Microsoft is making 180-degree flips on policy something of a habit this year. As such, IT professionals could be forgiven for clinging to any hope that the company will reverse its decision to end its TechNet subscription service, a move that has drawn further ire from developers since it was announced in July.
Windows 8.1 is set to bring with it a slew of tweaks and improvements to Windows 8, including a new lock screen slideshow function, a more colourful Start screen, different tile sizes, enhanced apps and more snap views.