The requirements list is very interesting.

For example:

> Meet the following functional requirements to ensure your app is using a web browser engine that provides a baseline of web functionality: Pass a minimum percentage of tests available from industry standard test suites: 90% from Web Platform Tests and 80% from Test262

And:

> Program security requirements: You must do the following: Use memory-safe programming languages, or features that improve memory safety within other languages, within the Alternative Web Browser Engine at a minimum for all code that processes web content;

Is WebKit written in C++? That language certainly isn't "memory-safe" (I am not dumping on C++ here!). I assume that Apple uses fuzz testing and static analysis to find memory safety issues. So... does WebKit pass this rule? Hmm... And, are there any browsers written in memory-safe languages? I assume they would be too slow (Java, C#, etc.) I'm not sure if Rust is considered memory safe here. (Can you have null pointer exceptions in Rust -- dereference a null pointer?)