Nim transpiles to C, C++, or JavaScript so it can run on nearly anything (Windows, Linux, MacOS, embedded to some degree, web browser...etc). Cobra appears to be .NET, so a little more restricted I guess.
Edit -
Sorry - that was rude. I should have elaborated.
Transpiling is a specific type of compilation that involves two languages with a similar level of abstraction.
Compilation involves languages with different levels of abstraction.
Nim offers a much higher-level abstraction than C, thus you could consider the process of converting Nim to C, a compilation process rather than a transpilation process.
Edit: Compiling def isn't wrong, but Transpiling is more descriptive to me as it indicates you're not going to assembly or machine language or something like that.
That's just how I look at it anyway.