By releasing periodic updates, we can enhance and expand Visual Studio to support the latest software development innovations for building and managing modern apps. For more information, see Visual Studio Updates and the Visual Studio Update KB Article.

PLEASE NOTE: This Community Technology Preview has not been subject to final validation and is not meant to be run on production workstations or servers.

For the Visual Studio update package: The recommended approach for upgrading Visual Studio on test workstations is installing the latest Visual Studio Update CTP on top of an RTM release or a previous CTP build of that Update. Visual Studio CTPs can be upgraded to a different build.

Supported Operating System
Windows 7 Service Pack 1, Windows 8, Windows 8.1, Windows Server 2008 R2 SP1, Windows Server 2012

Please see the corresponding 2013 release for specific system requirements:
Source: Download Microsoft Visual Studio 2013 Update 5 CTP 3 from Official Microsoft Download Center