Plesk 10.x and 11.x allows creating many domains/subdomains pointing to the same document root. However, this is only possible to do in a scope of a single subscription. Two domains on different subscriptions cannot share single document root.
For Plesk 9.5 and earlier, following solutions can be applied:
- Create many domain aliases under single domain.
- Create frame-forwarding hosting for each additional domain and point them to the main domain.