Release 5U1 Web Server is a maintenance release that fixes bugs in Release 5 Web Server. Release 5 Web Server was a feature release with respect to Release 4. It has a number of new features and interface enhancements.
Release 5 Web Server introduced a new administrative infrastructure with new administrative tools. The administrative infrastructure includes an Administration Server instance which hosts configuration information for any number of Web Server instances. A new command line interface (wadm) and a new graphical user interface are used to create Web Server instances, either locally or on remote computers, and to configure and manage these instances. The new administrative tools require an administrator user name and password.
For more information about the new administrative infrastructure introduced in Release 5 Web Server, see Web Server 7.0 Administrator's Guide.
These changes in the Web Server administrative interface have a significant impact on upgrade.