Some people might not know it, but on https://stackapps.com/ there are several applications / user scripts available which makes certain tasks easier for moderators and other users which often post helpful comments.

I like to point out some of them here. Feel free to post other ones as answer posts.

These user scripts require the Greasemonkey extension for Firefox. Modern versions of Opera and Chrome should also support them directly. After installing the extension, then user scripts can be installed by clicking on the Install link which should pop up a installation dialog.

Copy Question Link Markdown - Making it easier to copy links to questions!

Adds a 'copy' link below questions and answers in the [title](url) form required for formatted links in comments. This is much better than posting the URL only or a "this" or "here" link.

SE Comment Link Helper

When submitting a comment, this script will turn all bare URLs to SE posts into the [title](url) form by looking up the title using the official API. It can lead to a short delay when submitting the comment. I use this sometimes to turn single URLs in comments of other users into the full form.

Easy way to copy code block?

See dedicated post.

User script for CTAN Package and TeXDoc.net buttons

See dedicated post