I am confused on whether I should install the userscript Greasemonkey.
Below taken from the 11/21/2017 Newsletter.
Web browser extension
We have a Web browser extension (userscript) that integrates Project-GC into Geocaching.com. Other improvements has also been added. To use it one needs for example the Greasemonkey or Tampermonkey plugins installed in the web browser. Firefox has recently moved on to version 4 of Greasemonkey which isn't compatible with old userscripts, our script was affected as well.
The userscript is however open-source and just hours after we added an issue about it on Github a pull request was submitted by a frequent user of Project-GC. Much appreciated!