1. A method for single-sign on of a user on a client machine to one or more target applications on target application servers in a computer information-processing network, comprising: accessing an access server from a browser on said client machine; entering into said browser user-specific access server logon credentials for logon and access to said access server and logging onto said access server; selecting a link to a target application of said one or more target applications from a linkpage presented to said browser by said access server, user-specific target application logon credentials for said target application having been previously stored in a registration database; after said selecting said link, said access server presenting to said target application said stored user-specific target application logon credentials for logon and access to said target application in a form and according to a protocol recognizable by said target application and thereby logging into said target application on behalf of the user and establishing a target application session; and establishing a target application session, bypassing said access server, between said client machine and said target application.