- #Python is written in C
- #Perl is written in C
- #Ruby is written in C
- #PHP is written in C
- #JavaScript engines started in C, now mostly in C++
- #Go was first in C, now written in Go itself
- #C++ compilers are written in C++
- #Swift is built with C++ and Swift (on LLVM in C++)
- #C# runs on .NET, built in C++/C#
- #JVM (HotSpot) is written in C++

Yet, people still doubt the necessity of learning C!

@mirsadra
When I was working on a project at work a while back that needed to use C++ a Java engineer coworker commented something like "I didn't think anyone really used that anymore"

My reply was "Someone has to write your interpreted language runtime for you"

@elfieclaire And, thanks to them, people can argue that 'we don't have to know it.'

That's the entire point of good engineering, creating robust abstractions so the next layer doesn't need to worry about the implementation details. The fact that we can have that debate is a testament to the success of the systems programmers who build our foundations!

It’s not about what you need to do to do your job; it’s about what you can understand to see the full picture.