Write markup without having to escape anything.
Instead of using <pre><code> elements, use <script type="text/plain">:
View source to see that the following didn’t need escaping (except for </script>, that does):
Why not use the HTML <template> tag?
Because it is a PITA to get its textContent and needs to be pointlessly cloned.
Feel free to implement it yourself and send a pull request though, if you are so inclined.
Can I use this inline?
Not out of the box, because I figured it’s more of a hassle to type <script type="text/plain"> than escape the 1-2 < characters you need to escape in inline code.
Also inline code is not as frequently copy-pasted, which was the major source of annoyance that got me to write this plugin.