I tested the Wormhole IT web conferencing system today and was very impressed with the quality of video and audio by multiple users. The system offers what most web conferencing systems have: Recording capabilities, Document sharing, screen sharing, Audio, Video (both for multiple users), whiteboard, and chat. It also provides options for document sharing such as: share in the whiteboard, download as pdf (no matter what your original format is) and download in original format. The host decides how to share the documents. This screenshot shows the conference area, with feature icons on top, whiteboard, participants list on the right, chat at the bottom, and one of the presenters' video.
It is not free or open source. I understand that the cost is way below its competitors (Elluminate and A. Connect) although their production quality is as good as the others we have tested.