| GitHub | GitLab | HackMD | Gitbook | Google Document | Dropbox Paper | |
| self-hosted | X | V | V | X | X | X |
| Markdown Support | V | V | V | V | X | V |
| Cloud-based or On-premises | Cloud-based | Both | Both | Cloud-based | Cloud-based | Cloud-based |
| Version-Control | V | V | V | V | V (version history) | V (version history) |
| Collaboration Features | Ｖ | Ｖ | Ｖ | Ｖ | Ｖ | Ｖ |
| CI/CD | V | V | X | X | X | X |
| Document Hierarchy Structure (Navigation) | X (Use directory to create hierarchy) | V | V | V | X | X (Use directory to create hierarchy) |
| AI Support (for analysis or Let chatgpt review your PR.) | V (by Actions) | V | X | X | X | X |
| Pricing | Free/paid | Free/paid | Free/paid | Free/paid | Free | paid |
Ref:
https://medium.com/itsoktomakemistakes/%E8%87%AA%E6%9E%B6-gitbook-%E6%95%99%E5%AD%B8-639118adea15