`mojs` definitely was created to support old and slow computers(it supports FireFox from version 4 and IE9).
The problems usually with the Chrome browser because it updates frequently and the Chromium team changes it a lot, so what was recently woking well might not work well right now. And problems like these are usually regard rendering performance and CSS transforms. So the issues you might see are related to the demos itself(not library) which were highly optimized for recent browsers' engines and those changed. I will revamp the demos shortly to keep them up to date.
Also, I often found that heavy animations work much better on mobile devices like iPhones than at my MacBook Pro mid 2012.
The problems usually with the Chrome browser because it updates frequently and the Chromium team changes it a lot, so what was recently woking well might not work well right now. And problems like these are usually regard rendering performance and CSS transforms. So the issues you might see are related to the demos itself(not library) which were highly optimized for recent browsers' engines and those changed. I will revamp the demos shortly to keep them up to date.
Also, I often found that heavy animations work much better on mobile devices like iPhones than at my MacBook Pro mid 2012.