eBay HTML 5 banners
I worked as a HTML 5 banner developer for over a year. We had to build an array of sizes that had to work in all major browsers (including the dreaded ie11).
To handle the animation we went with the JS library Green Sock. It suited our needs to be backwards compatible with old clients and to have the animations be on a timeline. That made it easy to read and update for all the devs in the team.
During my time working on the banners for eBay, I had to use Google web designer for some campaigns which were pretty interesting as an all in one banner tool.