London-based startup Openads has changed its name to OpenX (see TechCrunch UK for more) and former AOL CEO Jonathan Miller has joined as chairman. OpenX is an increasingly popular open-source ad server (we use it here at TechCrunch). Since his departure from AOL, Miller has become quite active in the startup world as an investor and board member. He is a partner in the Velocity Interactive Group with former Fox Interactive Media chief Ross Levinsohn. Miller also sits on the board of Clickable, another advertising startup in which he has personally invested.