Syncfusion has provided an in-browser environment where you can write, compile and run code that uses Blazor components and get it previewed live. https://www.i-programmer.info/news/89-net/17118-explore-syncfusions-blazor-playground.html
WinterJS is a brand new Javascript runtime by Wasmer which comes with the claim that it's the fastest of them all. Let's find out if that holds true. https://www.i-programmer.info/news/167-javascript/17111-the-winterjs-javascript-runtime-is-asking-for-your-attention.html