Bookmarklet

When clicked, bookmarklets can perform a wide variety of operations, such as running a search query from selected text or extracting data from a table.

[1] Steve Kangas of bookmarklets.com coined the word bookmarklet[2] when he started to create short scripts based on a suggestion in Netscape's JavaScript guide.

[6][7] William Donnelly created a work-around solution for this problem (in the specific instance of loading, referencing and using JavaScript library code) in early 2015 using a Greasemonkey userscript (Firefox / Pale Moon browser add-on extension) and a simple bookmarklet-userscript communication protocol.

Note, however, that if/when browsers support disabling/disallowing inline script execution using CSP, and if/when websites begin to implement that feature, it will "break" this "fix".

An immediately invoked function that returns no value or an expression preceded by the void operator will prevent the browser from attempting to parse the result of the evaluation as a snippet of HTML markup: Bookmarklets are saved and used as normal bookmarks.

For example, they can: "Installing" a bookmarklet allows you to quickly access and run JavaScript programs with a single click from your browser's bookmarks bar.