Very nice visually, but it doesn't look like it's accessible (#a11y). And, this makes accessibility even harder, but I'd like to see more interactive simulatio

Very nice visually, but it doesn't look like it's accessible (#a11y). And, this makes accessibility even harder, but I'd like to see more interactive simulations and tools rather than passive animations, like at http://www.socr.ucla.edu/ http://www.socr.ucla.edu/ and http://phet.colorado.edu/ http://phet.colorado.edu/