Requirements: Good Comment System for Static Websites

Following up on previous previous post I am collecting here a requirements for good comment system for static websites, mainly blogs:

Non-functional requirements

• Simple installation. This is one of the main requirements, you can furthe split it by:
  • Number of server components needed to run. Less is better.
  • Integration into static website
  • Things like domains, SSL, reverse-proxy, etc.
• Performance. One of the reason for popularity of static website generators is that they provide really high preformance, comment system should also be performant, which can be split in two factors:
  • Size JavaScript components
  • Latency in receiving comment list from server
  • Complexity of HTML layout
• Easy administration. Comment system should not distract authors from creating contains, but still provide basic functionality you expect: editing, deleting, banning, moderation
• Security. It should not be possible to delete/edit/modify other people comments, also it should not be possible to spam or abuse comment system
• Visual appeal. It should be nice to use them.

Functional requirements

• Allow anonymous comments
• Multiple nesting level. There are different opinions out there is multi (2+) levels of nesting are good, but coment system should allow flexibility and pick some setting as a default
• Self-service functions - Users should be able to edit/delete their own comments withing certain time interval after positing it
• Ability to like/dislike comments to incentivise constructive discussion
• CAPTCHA/SPAM protection
• On-Demand loading. Comes from performance: if you have very actively discussed post, it does not make sense to load comments before user actually reached them in viewport
• Adaptive layout. You should be able to read comments from mobile phone
• Import from existing comment systems to drive adoption (disqus, isso, etc)

I think this is bare minimum for a useful comment system.