Version 2.0 is the GN4 version, released on December 10, 2013.
This chapter lists the new and improved features, added capabilities, performance improvements, and bug fixes in the version 2.0. See also Version 2.0 updates for additional bug fixes.
For the full list of all changes and bug fixes, go here: http://tech.teradp.com/tech/html/GNPortal/default.asp?link=relnotes2.0.html.
IMPORTANT: since the version 2.0, Windows XP, Windows Server 2003, and IIS 5 are no longer supported due to Microsoft Framework 4.5 compatibility restrictions.