I do not know if it will, or will not, install on a DreamHost shared server. I looked at the specifications document but it did not have a clear set of system requirements. It did, however, include this text:
"The dimdim back end has two servers – Conference Server and a Streaming Server. The conference server hosts all the conferences taking place on that server while there is a dedicated streaming server for each conference server."
Theses statements alone indicate that whether or not you could succeed in installing it, doing so would not be allowed on a DreamHost shared account, as stated in the Terms of Service and clarified in the DreamHost Wiki.
--DreamHost Tech Support