Red5chat provide you all the necessary requirements that you could imagine to develop you website. It is open source software, so you could make your necessary improvements too. The best part is that there is no need for extra plugins or add-ons. Check out http://www.red5chat.com for complete info.
Openmeetings is simply designed for online conference. Apart form screen and document sharing, it also let you to record and save them. It also supports all the popular document files and allows the user to edit images on whiteboard by just dragging and dropping them. With multi-linguistic support it also translates your language to the one you desired. More on http://code.google.com/p/openmeetings/
For recording and playing it back, there is nothing better than red5-recorder. Download it, customized it and use it as per your needs because this is also a open source software. For complete detail visit http://www.red5-recorder.com/