WebAssembly is an open standard with multiple open source implementations that come as a default install with every browser, whereas Java was a proprietary, clo

WebAssembly is an open standard with multiple open source implementations that come as a default install with every browser, whereas Java was a proprietary, closed source, at-the-time-still-patented technology that some browsers would license for embedded distribution, but which by and large was an after-market installation by the end user.