SocialEngine - Socialengine PHP: Elevating Your Online Community Experience.
eXo Platform - Digital workplace solution
JomSocial - Open Source Social Networking Software. Award winning open source community software by JomSocial. This social networking software is widely used by many Joomla users.
Basecamp - A simple and elegant project management system.
phpFox - phpFox is a powerful social network platform for niche communities
Slack - A messaging app for teams who see through the Earth!