Single sign-on systems allow users to log in to a number of heterogeneous software applications and computers with the same set of credentials (e.g. username and password). Despite the advantages of these systems concerning user experience, security, policy enforcement and others, they are rarely implemented in small organizations. This thesis focuses on the implementation of a web single sign-on system in a small organization. There are three main components in this specific system: a LDAP server, the SSO server itself and a user management application. The former two are off-the-shelf software components that had to be selected, installed and configured, while the latter is a custom application.