They have in a limited fashion in the past, I don't recall which hardware was supported. There is also Good Technology too - Motorola bought them a long time ago:Any word if RIM will ever make their Enterprise Apps available for other platforms? My employer doesn't provide support for anything else b/c they run such a secure network
http://www.bbhub.com/2006/11/10/motorola-to-acquire-blackberry-competitor-good-technology/