Padlet is the easiest way to create and collaborate in the world
tiddlyspace - bring your thoughts to life
TiddlyWiki — a non-linear personal web notebook
Client Portal, File Sharing, Teamwork & Collaboration platform
Confluence - Team Collaboration Software | Atlassian
Lessons Learned Server
Your online project management software tools - Wrike
Huddle: The Enterprise Content Collaboration Platform
Knorbit
Rizzoma—wiki based collaboration service.
Notion - an expressive and collaborative document editor
SlimWiki — Beautiful Wikis for Teams
Universal Edit Button - Universal Edit Button
Create a Wiki - Intodit.com
Swirrl: Online Database Software
Wikidot - Free Wiki Hosting
WikiMatrix - Compare them all
Coworking Wiki
Wikia - Wikia
Central Desktop - Team collaboration, task and project management software - Central Desktop