From the website: "Recogito is an online platform for collaborative document annotation. It is maintained by Pelagios, a Digital Humanities initiative aiming to foster better linkages between online resources documenting the past.

Recogito provides a personal workspace where you can upload, collect and organize your source materials - texts, images and tabular data - and collaborate in their annotation and interpretation. Recogito helps you to make your work more visible on the Web more easily, and to expose the results of your research as Open Data."