[This API now exists as Planview PPM Pro WS. This profile is being maintained purely for historical and research purposes.]
From their site: With projects and resources as the core data elements in Project Portfolio Management (PPM), it is often necessary to integrate PPM with other applications to fully automate and manage a business process. As a customer of Innotas, you can take advantage of the Innotas API to create integrations. Web Services are included for the following entities: Program, Project, Resource, User, Account, Contact, Task, Timesheet, Request, and Issue.