In .NET you can also embed CPython​ using pythonnet:

https://github.com/pythonnet/pythonnet

nuget does not work

Pyjion is C Extension based JIT for CPython. Pyjion only uses CoreCLR RyuJIT as a JIT compiler backend. It is NOT aware of .NET types at all.

Note that you can use pythonnet for interop between CPython and .NET for both embedding and extending.

DLR is just dynamic runtime for dynamic languages, including IronPython, IronRuby, PowerShell, COM interop calls. JIT is for CLR runtime to compile IL byte-code.

Michael Kennedy mentioned on podcast that Dropbox is considering Python 3 with type hints. Pyston is Python 2 only and considerable effort would take to make it work for Python 3.

PyPy is not that bad as they describe it in incentives to start Pyston. PyPy now has cpyext and Python 3.5 support is funded by Mozilla.

Another reason is pluggable JIT to CPython such as Pyjion. This is already possible in Python 3.6.

Currently you can use Cython for hot spots in your CPython apps and even release GIL.

"the [speed] difficulties come from Python's extremely rich object model, not from anything about its dynamic scopes or dynamic types. The problem is that every operation in Python will typically have multiple points at which the user can override the behavior, and these features are used, often very extensively. Some examples are inspecting the locals of a frame after the frame has exited, mutating functions in-place, or even something as banal as overriding isinstance."

It's not typing that's the problem, it's dynamic behavior like monkeypatchable methods which require dict lookups.

Nowhere did I state that typing is the problem. I was explaining potential move to Python 3 with mypy.

.NET is highly backwards compatible, so why does "10+ year of answers to the same questions" matter to you?

I would say it is in both directions ;)

you can develop WPF apps with pythonnet and then ship with PyInstaller

You can also use pythonnet with F#

MS open-sourced IronPython and the development is driven by the community now.