Which tool to choose for creating and publishing a roadmap?

Question

Software and Internet Services

There was a need for a convenient tool for working with roadmaps and their subsequent publication, in order to make visual plans for the development of opensource projects that have already been published or are being prepared for this.
Necessary:

• Online service
  
• Convenient export, for example: embed, image, html & etc.
  
• Free (at least basic functionality), or sane cost
  
• Not a harvester: no need for a project/development management tool, etc. - narrow-purpose tool
  

Desirable:

• Convenient
  
• Attractive (customizable) appearance of published "maps"
  
• Integration with trackers or task schedulers, for example: trello, youtrack
  

Allowed:

• If not as a service, then with the ability to install on your server
  

Answer 1

Ladies and gentlemen, if there is no such tool, let's develop it.

Answer 2

How about aha.io?