Attribute (source) is a user script to easily copy an HTML snippet giving attribution to a Wikipedia article. It generates output in this format:

From <a href="https://en.wikipedia.org/wiki/Open-source_software"><i>Open-source software</i></a> on <a href="https://en.wikipedia.org/wiki/Main_Page">Wikipedia</a>, the free encyclopedia. Text is used under the <a href="https://en.wikipedia.org/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License">Creative Commons Attribution-ShareAlike 4.0 International</a> license.

When displayed, it looks like this:

From Open-source software on Wikipedia, the free encyclopedia. Text is used under the Creative Commons Attribution-ShareAlike 4.0 International license.

This feature is accessed using the "Copy attribution" link in the "Tools" menu.