Pop-up ad

The pop-up window containing an advertisement is usually generated by JavaScript[1] that uses cross-site scripting (XSS), sometimes with a secondary payload that uses Adobe Flash.

[4] Web development and design technologies allow an author to associate any item on a pop-up with any action, including with a cancel or innocent-looking button.

[citation needed] In the early 2000s, all major web browsers except Internet Explorer let users block unwanted pop-ups almost completely.

In 2004, Microsoft released Windows XP SP2, which added pop-up blocking to Internet Explorer.

Because this is a typical response, some authors of pop-up advertising depend on this and create on-screen buttons or controls that look similar to a "close" or "cancel" option.

Pop-under ads do not immediately impede the view of content, but remain unnoticed until the user closes or minimizes the main browser window.

A pop-under ad involves two JavaScript functions introduced in 1995 with the Netscape 2.0b3 browser.

Most modern browsers allow window.open to execute only if it was called by a user interaction (e.g., a mouse click) event handler.

'555 is related to the method of opening an exit pop from a toolbar or software application on a computing device, whereas '229 covers the method used to open an exit pop from an embedded script found within a media file (e.g., JavaScript code on a web page).

Copyright aspects of pop-up advertising are discussed in the Wikipedia articles on derivative works and transformativeness.