Wikipedia TeX Source Extractor
A GreaseMonkey script that allows you to get the TeX source behind a formula on Wikipedia.
Earlier today I wrote a little GreaseMonkey user script called Wikipedia TeX Source Extractor (WTSE).
If you ever felt the need to copy the TeX source of a formula while reading various mathematical entries on Wikipedia, WTSE will help you achieve that. Once you click on the desired formula, a textbox with the formula's TeX source already selected will appear; you now only have to hit CTRL-C and you're good to go. It's as simple as that.
You can install WTSE from its userscripts.org page, or you can fork it from GitHub.