Because so many people have asked, here's a full tech tree. Note that most Warzone technologies have more than one prerequisite, so you'll have to click through to see all the prerequisites.
Many Warzone technologies have more than one prerequisite, so they're listed under their first prerequisite, and subsequent prerequisites just have a "See above" link to where they're first mentioned.
Some random statistics: There are 428 technologies. Stormbringer Emplacement takes the longest to research. EMP Mortar has more prerequisites, though, but you can theoretically get it faster because you can spread them out over many research facilities. Other technologies with many requirements include Missile Fortress, Mass Driver Fortress, and Plasmite Bomb.