This patch replaces the original Bungie-esque ammo displays for both the Rail Gun and Mortar Launcher with more suitable versions. Gameplay has not been altered, the only difference is that the HUD ammo display is much improved for these weapons.
The Marathon EVIL Sights Patch gives you sights (so you know where you are shooting) in Marathon EVIL. The sights pinpoint exactly (almost) where the bullet, missile, etc., will hit.