I have been keeping lists of urls in https://gist.github.com as markdown files. Someone even made a shortcut http://gist.new/

It has been very useful. URLs are super easy to modify, super easy to share, super easy to open, add notes etc. Having a gist adds the ability to share a set or URLs and people can comment on them.

I could (if i want to) use github API and a browser extension to put bookmarks directly in a gist as plaintext