This is a prototype intended for map makers to start going. Gameplay probably won't change much, but gamemode's structure certainly will.

Two gamemodes in one:

The Horde Project - As Survivors, defend your control points against Zombies until the time runs out. Survivors do respawn. 8 Survivors vs 16 Zombies.

Zombie Fortress - As Survivors, capture a series of control point until the time runs out. Survivors become Zombies upon death. The game start with 4 Zombies and Zombies have to snowball their numbers.

In both gamemodes BLU are the attackers, regardless if they are Survivors or Zombies.
Set up your map like it's an Attack/Defense map, and then add stuff from horde_template.vmf packaged with the gamemode.
Eventually these entities will move into vscript itself.

The default mode is ZF. To switch to Horde you need to go to custom\horde_project\scripts\vscripts\zombiehorde\horde.nut
and change line 15 from
::infection <- true;
to
::infection <- false;

Balance chances in comparison to Vanilla TF2:
* Sentries of both teams deal only 25% of their normal damage.
Zombies:
* Zombies can use only melee and some other non-damaging weapons (e.g. Jarate, Sanvdich, Gas Passer).
* Zombies can wall-climb by hitting walls exactly like in VSH-VScript.
* Zombie Engineers' max metal reduced to 130.
* Zombie Pyro's Gas Passer recharges in 15 seconds instead of 60.
* Zombie Soldier's Banners charge passively and take around 25 seconds to fully charge.
Survivors:
* All miniguns deal only 60% of their normal damage.
* Melee weapons mini-crit on classes other than Engineer and Spy.