[diggan]

From the README:

> Project goals: Both-way interoperability, Full .NET compatibility, Security, Cross-platform development, Increased performance - https://github.com/peachpiecompiler/peachpie

So seems they're aiming to use the PHP language but on a different runtime, for the listed reasons. Sounds kind of out there, but seems at least the .Net Foundation supports it, I'm guessing for the same reasons.