[HdS84]

C# has unsafe, which extremely powerful. See ravens repo for heavy usage of that.

Otherwise python is also a good example of that. First start out in python. Not fast enough? Bring in python, which compiles down to c. Id that's not enough, drop to raw c.

[sega_sai]

I mostly use python, but switching from python to C is IMO too much work. What would be great if within one language, there was an access to much stricter/faster language. I.e. imagine writing a python function that is strictly typed, and does not use any of the python-isms with __methods that would be more verifiable and faster. I guess cython has a bit of that approach, but it's not that compatible with regular python.