| Title | CMS Category |
|---|---|
| OpenEMM | CRM Solutions |
| OpenEMR | Specialized CMS |
| OpenMRS | Specialized CMS |
| OpenProject | Groupware |
| OpenWGA | Enterprise Solutions |
| OrangeScrum | Groupware Wiki Software |
| OroCommerce | Traditional CMS CRM Solutions Ecommerce DAM Software |
| OsClass | Specialized CMS |
| osCommerce | Ecommerce |
| OSSN | Social Network Solutions |
| osTicket | CRM Solutions |
| Oxwall | Social Network Solutions |
| Pangea CMS | Specialized CMS |
| Paradiso | E-Learning |
| Passion.io | App Builders E-Learning |
| Payload | Headless CMS App Builders Ecommerce DAM Software |
| Perch | Traditional CMS |
| Percussion | Enterprise Solutions |
| PhotoPrism | Gallery Software |
| PHP Melody | Gallery Software |