The number of solutions being built on top of Content Management Systems is plenty and across implementations, you wish that there was a common API that you could access all the CMS. CMIS is the common API via which you can access any Content Management System that supports this standard.
The book starts off with an overview of CMIS and how it came about. The next set of chapters goes into the CMIS Standard, especially the different operations via which you can do create, update, delete and query for documents. These two chapters setup a solid foundation since they allowed you to understand what is happening behind the scenes in terms of the REST Calls and the data formats being exchanged in the request / response.
I preferred this approach rather than jumping into a high level API that does not allow the developer to understand some of the details behind the calls. The next chapter jumps into specific support for CMIS via Alfresco.
The final couple of chapters delve deeper into integration scenarios with the Drupal Web Content Management (WCM) and Mule ESB Integration.
Overall the book is a solid guide to the CMIS Standard via Alfresco. In case you are planning on integrating with any CMIS capable repository, keep this book handy.