HTML5 is is the fifth revision of the HTML standard and has amazing multimedia capabilities built into it unlike previous iterations. It is fast taking over the space once occupied by Flash. Animations, slideshows are possible with HTML5.
HTML5Maker is a new app that allows you to do animations easily in HTML5. I see that the free version only allows one animation, I’m sure there are other freeware applications for HTML5. Do a search on Google.