Generally banners are created in a GULP environment, using a command line set of functions to run, build and export all banners. Animations are usually Greensock, but sometimes JS, CSS or other 3rd party engines are used. These examples are all of the GULP/Greensock variety.
Ironwood :: 300x250 Ironwood :: 300x600 Lumryz :: 300x600 Lumryz :: 728x90 Lumryz :: 160x600