Like the Pfhor, the Compilers come in ranks. The Compiler has two ranks: the Minor, which wears an orange cloak, and the superior Major Compiler, which wears a purple cloak.
The Compilers attack by shooting a bolt of energy out of the machinery they have hidden under their cloaks. The bolt is powerful, but slow, so the player can move out of its way given sufficient distance to react. When the Compiler is struck by an attack, any impending attack is interrupted.
Some Compilers also use a cloaking device which make them harder to spot. While most of the time the Compilers are enemies to you, in some levels they are allies rebelling against the Pfhor.
Appearance and Physiology
The Compilers wear a long robe like cloak that covers internal machinery. Their heads are somewhat dome shaped. In Marathon they have a long cord or tail coming out of the back of their heads, but in Marathon 2: Durandal the tail is gone. Note that Compilers have two small green lines on their heads in Marathon Infinity, possibly from the glow.