It's says they actually get WordPress running before releasing it. Not that I want to undermine project achievements, but WordPress likely going to work even on PHP 5.2.x that almost 10 years old.

My point was that WordPress is a large codebase and exercises a fair amount of php syntax and built-ins.

5.2.x is old, but that doesn't mean it's simple or easier to implement.

You're right, 7.0 for example deprecates/removes some dirty practices that are hard to implement in .NET

'Sort of running' and stable enough to deploy into production are different things. I really want this to work but I am a little nervous about committing to it.

It was running with modifications at the time, but now runs unmodified. I suggest to get in touch with the team to discuss your specific case at info at iolevel dot com.

Probably a good idea. For us this would be huge if it worked but it's pretty scary...