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.

>>4
I'd just like to interject for a moment. What you're referring to as C++, is in fact, C/C++, or as I've recently taken to calling it, See plus See plus plus. C++ is not an programming language unto itself, but rather another component of a fully functioning C/C++ system made useful by the C corelibs, stdio.h utilities and vital system components comprising a full C/C++ programming language as defined by the ISO/IEC 14882 standard.