Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
DocuShare - Enterprise content management & process automation platform
Notion - All-in-one workspace. One tool for your whole team. Write, plan, and get organized.
M-Files - M-Files is an enterprise information management system that helps users with organizing and managing documents.
Slack - A messaging app for teams who see through the Earth!
IBM FileNet - Enterprise Content Management platform for large businesses