Acquia - Acquia is a commercial open-source software that provides products, services and technical support for the open source Drupal social publishing system.
IBM FileNet - Enterprise Content Management platform for large businesses
Structr - Open-source data CMS platform.
OnBase - OnBase is an enterprise content management and process management software suite.
Alfresco ECM - Alfresco ECM is an Open Source Enterprise Content Management Platform
Adobe Experience Manager - Adobe Experience Manager is a cross-platform CMS that works across websites, mobile apps and on-site displays.