Hacker News

 Hacker News  is a bookmark posting silo as well as a silo for comments on those links. Previously Hacker News was described as a link aggregator, however that implies a level of automation which it lacks. Links are manually posted on Hacker News by humans, and thus resemble bookmark posts more than aggregation.

Features

 * login
 * bookmark posts, which you can then interact with:
 * like - called upvote in their UI.
 * number of likes/upvotes of the post displayed as "points"
 * comment, which you can then interact with:
 * like
 * number of likes of the comment displayed as "points"
 * comment, which you can then interact with again, recursively.

Community Examples
Members of the IndieWeb community who post (what they call "submit") bookmarks and/or comments on/to Hacker News:
 * submissions, comments
 * submission
 * submissions, comments
 * submissions,comments
 * comment
 * comment
 * submissions, comments
 * submissions, comments
 * , comments submissions from domain

POSSE to Hacker News
If you post bookmark posts, you could POSSE them to Hacker News, if you have an account there.

If you post to Hacker News, you should consider posting bookmark posts to your own site instead, and then POSSEing to Hacker News.

Examples:
 * 2012-10-07 https://aaronparecki.com/2012/10/07/1/providing-apis-for-content-driven-websites
 * POSSE copy: https://news.ycombinator.com/item?id=4624105

POSSE replies to Hacker News
If you post comments on Hacker News, you should consider instead posting a reply on your own site, and then POSSEing that reply to Hacker News.

Examples:
 * 2017-06-08 https://aaronparecki.com/2017/06/08/9/indieweb
 * POSSE copy: https://news.ycombinator.com/item?id=14516923

POSSE likes to Hacker News
If you upvote posts or comments on Hacker News, you should consider instead posting like posts on your own site, and then POSSEing those likes as upvotes to Hacker News.

Backfeed responses on Hacker News
If you POSSE to Hacker News, you should also backfeed any responses (replies, votes) back to your original post.

has done some manually, but has considered using https://hnrss.github.io/ to automate it

Bridgy Support
There is no known Bridgy support to POSSE (e.g. bookmark, comment, or like) posts to Hacker News or backfeed responses (yet). Upvote or help implement:
 * Bridgy Github: hacker news support: publish, backfeed #693