The development timeline for Total Annihilation Zero is chronicled below.

January 2009 TA: Excess II development begins!
April 2009 Project announced to the public.
July 2009 First playable build compiled.
September 2009 Version Alpha 1 released to the public, featuring Arm and Core T1 land and air units.
October – December 2009 Alpha 1b through Alpha 1e updates released.
June 2010 Version Alpha 2 released, featuring major changes and the addition of Guardians of Kadesh T1 land and air units.
July – November 2010 Alpha 2b through Alpha 2f updates released.
January 2012 Name changed from TA: Excess II to TA Zero.
January 2012 Official website launched.
January 2012 Version Alpha 3 released, featuring major changes and the addition of T1 sea units for all factions.
March 2012 Alpha 3b update released.
November 2012 Alpha 3c update released.
October 2013 Version Alpha 4 released, featuring major changes, the introduction of the megamap, the addition of T2 ground units for all factions, and the adoption of the new TA Unofficial Patch based installer format.
June 2017 Version Alpha 4b released, featuring major changes, a complete overhaul of all unit scripts and weapon firing effects, and the addition of new T1 and T2 units for all factions, including the first T2 aircraft and T2 shield generators.
June 2018 Version Alpha 4c released, featuring a variety of adjustments and bug fixes, new T1 transport aircraft and floating perimeter defences, and reworked projectile models.
January 2019 Map pack version 1c released, featuring a wide variety of new map features, three new maps, remakes of oldest two maps, and rest of the maps overhauled.
December 2019 Version Alpha 4d released, featuring a large amount of adjustments and bug fixes, reworking parts of oldest unit models, a complete overhaul of all weapon sound effects, and new water and lava splash animations.
April 2020 Map pack version 1d released, featuring one new map and updated map features for oldest two maps.