Permanently connect JS to a page by domain?

Question

Google Chrome

It is necessary to connect JS all the time the same script on the vk.com domain (for example), but what if even if you restart or close the browser and connect, it remains, how to do it?

Answer 1

It's called userscript . There are several browser extensions that can connect them - greasemonkey, tampermonkey. If my memory serves me, the opera could do it without extensions.
There is a similar thing for css - userstyles, stylish.