COLS is a combination of an OODBMS and a business logic server. With the logic on the server side, and a common protocol, multiple clients can connect to the same system. Built-in authorisation and authentication functionality provides granular control over the users of the system.

The goal is to provide an easy-to-set-up and easy-to-use, yet highly flexible and expandable server-client system.

The COLS project includes the server - called COLS - and common components such as protocol documentation, client libraries, etc. The clients have their own projects.