The MOT and evaporative cooling have been the mainstay for production of ultracold and quantum degenerate atomic species for that last 25 years.  We discuss the implementation of these techniques for diatomic molecular species.  This talk will focus on evaporative cooling of the hydroxyl radical (OH) in a magnetic trap.   We use forced microwave evaporation to eject OH molecules from the trap and reduce the OH sample temperature from 50 mK to 5 mK.  We will also briefly discuss the demonstration of a transverse 2D-MOT for a molecular beam of yttrium monoxide (YO) and progress towards a 3D-MOT.