ManageEngine RecoveryManager Plus - RecoveryManager Plus is one such enterprise backup solution which has the ability to easily backup and restores both the domain controllers and virtual machines.

Baïkal - Cal and CardDAV server

Heroku Enterprise - Heroku Enterprise is a flexible IT management for developers that lets them build apps using their preferred languages and tools like Ruby, Java, Python and Node.

Radicale - The Radicale Project is a complete CalDAV (calendar) and CardDAV (contact) server solution.

SECDO - SECDO offers automated endpoint security and incident response solutions

SOGo - SOGo is groupware server with a focus on scalability and open standards.