WordItOut - WordItOut is the word cloud generator that gives you control with many custom settings.
Documize - Enterprise-grade wiki and knowledge management platform
Wordsalad - Wordsalad is an app for generating “word clouds” from text that you provide.
HackMD - Fast and flexible, real-time collaborative markdown, inspired by Hackpad.
TagCrowd - Create your own tag cloud from any text to visualize word frequency.
ReadTheDocs - Spend your time on writing high quality documentation, not on the tools to make your documentation work.