The general WebKit/web browser stack is huge and has tons of room for error. This has been seen with the history of jailbreakme.com, and things like crashsafari.com 

Safari has run in a special sandbox for a while, and iOS now provides an API for a web view that runs in their own separate process like SFSafariViewController. 

It's still not all that difficult to mitigate this, considering many iOS apps do use web views that are in less restrictive sandboxes, like the App Store. However, you won't get JIT if you want to run in your own process.

__Font Stacks__

TODO