| IAttributed | Inherited by interfaces that support both reading and writing attributes |
| IAttributedReadOnly | Inherited by interfaces that support reading attributes |
| IBranch | Each PIV is associated with one branch. Several branches can be associated with one PI |
| ICommonspace | Represent a connection to Pro/INTRALINK |
| ICommonspaceProductItem | Product Item ("PI") within Commonspace |
| ICommonspaceProductItems | Collection of ICommonspaceProductItem objects |
| ICommonspaceProductItemVersion | PIV |
| IConflict | A check-in conflict |
| IFolder | Folder within Pro/INTRALINK Commonspace |
| ILifeCycleObject | Wraps Pro/INTRALINK LCO object |
| ILocalDatabase | Represents a local Pro/INTRALINK database we are currently connected to |
| ILocalDatabases | Collection of ILocalDatabase objects |
| IReleaseLevel | Encapsulates Pro/INTRALINK release level |
| IReleaseScheme | Encapsulates Pro/INTRALINK release scheme |
| IRTP | Encapsulates a "Request to Promote" form |
| IRTPFormInfo | Manages data needed for "request to promote" form creation |
| IServer | Root object of the whole Pro/INTRALINK COM Server |
| ITransactional | Base for classes that operate within contexts of transactions |
| IUser | Encapsulates one Pro/INTRALINK user |
| IUserGroup | Represents Pro/INTRALINK group of users |
| IWorkspace | Encapsulates Pro/INTRALINK Workspace |
| IWorkspaceProductItem | Encapsulates Pro/INTRALINK Product Item when it is checked-out to Workspace |
| IWorkspaceProductItems | Collection of IWorkspaceProductItem objects |
| IWorkspaces | Collection of IWorkspace objects |
1.5.1-p1