The patch contains various bugfixes and game improvements such as widescreen support, and provides some GUI tweaks. It also enables the use of the FMSel fan mission loader frontend with Thief 3 and bundles the most important T3 mods. It works with the GOG and Steam versions of the game.
Unofficial patches for the Thief 3 Editor: Have multiple independent editor installs, launch the patched game exe through "Send to Xbox", generate IBT files easily.
This patch is only for T3 mappers - not relevant for playing the game. Please go here for details. 1.1.10 includes files from the game edition.