C++ FAQ Celebrating Twenty-One Years of the C++ FAQ!!!
(Click here for a personal note from Marshall Cline.)
Section 6:
6.1 Is C++ a practical language?
6.2 Is C++ a perfect language?
6.3 What's the big deal with OO? Updated!
6.4 What's the big deal with generic programming?
6.5 Is C++ better than Ada? (or Visual Basic, C, FORTRAN, Pascal, Smalltalk, or any other language?)
6.6 Who uses C++?
6.7 How long does it take to learn OO/C++?
6.8 What are some features of C++ from a business perspective?
6.9 Are virtual functions (dynamic binding) central to OO/C++?
6.10 Why do virtual functions (dynamic binding) make a big difference?
6.11 Is C++ backward compatible with ANSI/ISO C?
6.12 Is C++ standardized? Updated!
6.13 Where can I get a copy of the ANSI/ISO C++ standard?
6.14 What are some "interview questions" I could ask that would let me know if candidates really know their stuff?
6.15 What does the FAQ mean by "such and such is evil"?
6.16 Will I sometimes use any so-called "evil" constructs?
6.17 Is it important to know the technical definition of "good OO"? Of "good class design"?
6.18 What should I tell people who complain that the word "FAQ" is misleading?
6.19 How can I help make the C++ FAQ even better??!??
[6.6] Who uses C++?

Lots and lots of companies and government sites. Lots.

The large number of developers (and therefore the large amount of available support infrastructure including vendors, tools, training, etc.) is one of several critical features of C++.