As the name implies, GitBook is a platform for publishing and managing books using Git and Markdown. It is quite clear how these 2 fit in, Git for revision control, and Markdown for formatting. The published book is hosted online, it can also be exported into various formats (i.e. PDF, MOBI, EPUB).
It is suitabled for publishing technical documents like
- API specifications
- Manual
- Research paper
- Tutorial
- Thesis