You can view installed modules if you have Administrator privileges.
http://<your_domain>:<your_port>/share/page/console/admin-console/module-package
You can also use the Repository Admin Console (Enterprise Only) to view installed Module Packages using the following URL:
http://<your_domain>:<your_port>/alfresco/service/enterprise/admin/admin-systemsummary
The System Summary includes information about installed Module Packages.
You can find out more about using the Repository Admin Console Repository Admin Console.