[aidenn0]

Pretty much every modern language (Zig, Rust, C, and C++ included) depends on a runtime. The C runtime is privileged because it is already present on all 3 desktop OSes.

It is also a lot smaller than most other runtimes, which makes bundling the C runtime with the program more palatable.

A "C-compatible library" is a library (i.e. a collection of functions) that is callable in the same way that functions written in C are called. Nearly all non-C languages provide a way to call C functions (because, again on all modern desktop OSes, the operating-system interface is written in C).

If everyone wrote OS interfaces in perl, then you would want to compile to a perl-compatible library. If the Lisp machines had won, then you would be compiling to a Common Lisp compatible library.

[justincormack]

That is somewhat conflating the calling convention and the runtime - C really doesn't have much that you can call a runtime outside the calling convention, although some libraries (eg pthreads say) have a little runtime which matters in practise for integrations, but these are libraries not parts of the language itself.

[aidenn0]

malloc and free are part of what I would consider a runtime. As are the file objects opened for standard I/O.

It's a very small runtime, but all the code before main is properly runtime initiation

[kazinator]

> The C runtime is privileged because it is already present on all 3 desktop OSes.

Yes, Ubuntu, Debian and Fedora.

On Windows, you don't get a C run time; you ship a MS Visual Studio run-time DLL if you're using Microsoft's tools (and not static linking), or something else with someone else's tools; maybe a CYGWIN1.DLL or whatever.

You get platform libraries like kernel32.dll and user32.dll; but those are not a C run-time. They are easy to call from C, but other than that, they are the OS run time.

Recently Microsoft has made an effort to create a "Universal C Run Time" for Windows; but I think you still have to download and ship that, and there may be reasons for someone to choose a different run-time. (E.g. needing a pretty detailed POSIX implementation.)

[aidenn0]

I thought msvcrt shipped with windows as early as XP; was I wrong?

[kazinator]

Even earlier; but that's a private system library you're not supposed to use.

Raymond Chen explains it: https://devblogs.microsoft.com/oldnewthing/20140411-00/?p=12...

Microsoft's new Universal C Run Time addresses the problem of there not being a C library on Windows that is for public use (every compiler vendor providing their own).