BLDC motors are effectively Steppers with three coils instead of two (often called 3-phase.) That means three half bridges and three PWM signals will turn the motor. In fact, if you open up a hobby ESC you'll find six mosfets and either an 8051 or AVR.

BLDC's usually come with built-in Hall effect sensors that help encoding position. If a BLDC doesn't have sensors (sensorless,) or they're being ignored, than you need to account for an initial unknown speed. That usually works when the exact speed is not critical or there is feedback from another source (back EMF or a thing being cooled, for those interested.)

There are of course specialized drivers for BLDCs. There's simpler/cheaper ones just for Fans and full-fledged 3-phase drivers that are driven by PWM inputs (and a few via SPI/I2C.) I personally haven't used these parts but Microchip has a variety of fan drivers like the MTD6502B or a more traditional 3-phase driver like the MCP8024.