Abstract: A method is presented for enabling single-sign-on functionality with applications that require user/client authentication using form documents. A server-side forms-based single-sign-on (FSSO) module resides between a back-end application and a user. The FSSO module is configured to scan for various incoming requests and outgoing responses that contain information that trigger the FSSO module to initiate a single-sign-on operation or to perform another action with respect to an ongoing single-sign-on operation. At some point in time, a back-end application sends or attempts to send an authentication form to the user in order to obtain authentication information for an authentication operation by the back-end application, and the FSSO module intercepts the back-end application's authentication process to act as an intermediate agent between the user and the back-end application.