In this web content, the author discusses how a small browser quirk in JavaScript turned into a useful tool for many people over the years. It all started in 1995 when Brendan Eich demonstrated JavaScript to a group of engineers at Netscape. JavaScript URLs, which allowed users to run JavaScript on any web page they were viewing, were created virtually from the beginning of the language. These URLs were bookmarkable and shareable, leading to the creation of various utilities like manipulating images, interacting with online services, and tipping website owners. Bookmarklets, which were limited in characters and focused on doing one thing well, became popular for their simplicity and utility. However, they were eventually overtaken by browser extensions, which were easier to manage and install.
https://thehistoryoftheweb.com/postscript/wait-whats-a-bookmarklet/