The Kolab Groupware Solution offers flexible Personal Information Management (PIM) for professional deployments in companies of almost any size. But since it is Free Software, it can also be used by individual users who care about being in control of their personal information.
Trello is a collaboration tool that organizes your projects into boards. In one glance, Trello tells you what's being worked on, who's working on what, and where something is in a process.
Substance is a fully web-based document authoring and publishing platform. With Substance, writers, journalists, scientists and everyone else who's interested in publishing can use an open platform for writing and sharing articles.
Draw, share and collaborate on online diagrams. Easy web flow chart, network diagram, mockup, wireframe, UML diagrams like Class, Sequence, & data flow and process flow diagrams. Creately - free web-based software for online diagram software
simple text editor for the web. Your text is saved on the web, and more than one person can edit the same document at the same time. Everybody's changes are instantly reflected on all screens. Work together on meeting notes, brainstorming sessions, homework, team programming and more!