Question: When was the version of Windows 8 from the company that Iceweasel was based on made accessible?

Knowledge 1: GNU IceCat
GNU IceCat, formerly known as GNU IceWeasel, is a free software rebranding of the Mozilla Firefox web browser distributed by the GNU Project. It is compatible with GNU/Linux, Windows, Android and macOS. [SEP] Knowledge 2: Windows 8
The developers of both Chrome and Firefox committed to developing Metro-style versions of their browsers; while Chrome's "Windows 8 mode" uses a full-screen version of the existing desktop interface, Firefox's version (which was first made available on the "Aurora" release channel in September 2013) uses a touch-optimized interface inspired by the Android version of Firefox. In October 2013, Chrome's app was changed to mimic the desktop environment used by Chrome OS. Development of the Firefox app for Windows 8 has since been cancelled, citing a lack of user adoption for the beta versions.
Knowledge 1: Windows Media Encoder
Windows Media Encoder (WME) is a discontinued, freeware media encoder developed by Microsoft which enables content developers to convert or capture both live and prerecorded audio, video, and computer screen images to Windows Media formats for live and on-demand delivery. It is the successor of NetShow Encoder. The download page reports that it is not supported on Windows 7. WME has been replaced by a free version of Microsoft Expression Encoder. The Media 8 Encoding Utility is still listed. WME was available in both 32-bit and 64-bit versions. [SEP] Knowledge 2: Windows 8
The three desktop editions of Windows 8 support 32-bit and 64-bit architectures; retail copies of Windows 8 include install DVDs for both architectures, while the online installer automatically installs the version corresponding with the architecture of the system's existing Windows installation. The 32-bit version runs on CPUs compatible with x86 architecture 3rd generation (known as IA-32) or newer, and can run 32-bit and 16-bit applications, although 16-bit support must be enabled first. (16-bit applications are developed for CPUs compatible with x86 2nd generation, first conceived in 1978. Microsoft started moving away from this architecture after Windows 95.)
Knowledge 1: Windows Media Encoder
Windows Media Encoder (WME) is a discontinued, freeware media encoder developed by Microsoft which enables content developers to convert or capture both live and prerecorded audio, video, and computer screen images to Windows Media formats for live and on-demand delivery. It is the successor of NetShow Encoder. The download page reports that it is not supported on Windows 7. WME has been replaced by a free version of Microsoft Expression Encoder. The Media 8 Encoding Utility is still listed. WME was available in both 32-bit and 64-bit versions. [SEP] Knowledge 2: Windows 8
Windows 8 development started before Windows 7 had shipped in 2009. At the Consumer Electronics Show in January 2011, it was announced that the next version of Windows would add support for ARM system-on-chips alongside the existing x86 processors produced by vendors, especially AMD and Intel. Windows division president Steven Sinofsky demonstrated an early build of the port on prototype devices, while Microsoft CEO Steve Ballmer announced the company's goal for Windows to be "everywhere on every kind of device without compromise." Details also began to surface about a new application framework for Windows 8 codenamed "Jupiter", which would be used to make "immersive" applications using XAML (similarly to Windows Phone and Silverlight) that could be distributed via a new packaging system and a rumored application store.

Answer: September 2013