It was also new some time ago with Internet Explorer https://stackoverflow.com/questions/26339276/what-is-behavior-url-property-in-css#26339480 https://stackove

It was also new some time ago with Internet Explorer https://stackoverflow.com/questions/26339276/what-is-behavior-url-property-in-css#26339480 https://stackoverflow.com/questions/26339276/what-is-behavio... Used to implement things like CSS3 rounded corners and other decorations https://github.com/lojjic/PIE https://github.com/lojjic/PIE