A web browser is basically like

A half-OS within an OS.

Emacs is a good example of a web browser that is a text editor.

A browser is quite a systems based program. Why they aren't programmed in C and only C is beyond me.

I'd also like to assert for a moment, web browsers are not an operating system unto itself, but rather another component of a fully functioning system.

Many computer programmers write systems using C++ every day. Through a peculiar turn of events, some programmers today are too incompetent to properly wield this tool and many users are not aware that standards can be established to define boundaries.