This article presents the evolution of an assistive robotic system, the Functional Robot with Dexterous Arm and User-Friendly Interface for Disabled People (FRIEND), from a robot supporting disabled people in their activities of daily living (ADL) into a robot supporting people with disabilities in real workplaces. In its fourth generation, FRIEND supports the end user, a quadriplegic individual, to work as a librarian with the task of retrospectively cataloging collections of old books. All of the book manipulation tasks, such as grasping the book from the book cart and placing it on the specially designed book holder for reading by the end user, are carried out autonomously by the FRIEND system. The retrospective cataloging itself is done by the end user. This article discusses all of the technical adjustments and improvements to the FRIEND system that are necessary to meet the challenges of a robot supporting a disabled person working on a regular basis. These challenges concern the shared autonomy between system and user, system effectiveness, safety in interaction with the user, and user acceptability. The focus is on both the vision-based control of book manipulation as a key factor for autonomous robot functioning and on an advanced human-machine interface (HMI), which enables the end user to intervene if the autonomous book manipulation fails. The experimental results of an in-depth evaluation of the system performance in supporting the end user to perform the librarian task are presented. It has been shown that working together, the FRIEND system and the end user had an overall success rate of 95%. These results may help to raise interest in the research field of workplace assistive robotics, establish new projects, and, eventually, supply such systems to the people whose working lives they could greatly improve.