Babylon JS or Three JS for Sumerian

Great question! Our open source Amazon Sumerian Hosts JavaScript library on GitHub supports both BabylonJS and Three.js. So you can feel free to use either. We tend to recommend BabylonJS for the following reasons:

• BabylonJS offers the BabylonJS Editor which provides visual editing capabilities very similar to what Sumerian developers were used to with the Sumerian editor.
• We provide a plug-in for the BabylonJS Editor that makes it easy to deploy your BabylonJS scenes to AWS Amplify with just a few clicks, much like the Sumerian editor's one-click publish feature.
• We currently have a broader and clearer set of example applications for BabylonJS than we do for Three.js. You can see videos of those examples in action in this YouTube playlist. You'll find the code for those examples in the GitHub repository linked above.