Dennis Ritchie: This has always been a bit of a mystery to me to understand in any kind of detail. Obviously the use of C[1] was during early times (meaning the '70s and much of the '80s) considerably encouraged by its use as the lingua franca of Unix during the period that Unix was growing in the research and academic community, and then when Unix was taken up as the software basis for the workstation industry of the '80s. This in turn had to do in part with the non-political nature of C and Unix (not tied to a power in computer hardware until post-1984). There were also technical and semi-technical aspects: the language turned out to be well-placed both for describing things at a high enough level so that portability across hardware was feasible, but simple enough in its requirements to make it cheap to implement.
Bjarne Stroustrup: C and C++ became popular because they were flexible, cheap, and more efficient than alternatives. C owes much of its initial popularity to the popularity of Unix. C++ owes much of its initial popularity to its high degree of compatibility with C.
It was very important success of C and C++ that AT&T didn't try to monopolize these languages, but allowed its researchers to support the creation of alternative implementations. Also, AT&T fully supported ANSI and ISO standardization of C and C++ as soon as these efforts started. There was no systematic marketing of C or C++ before they became established languages and multiple vendors started competing. This non-commercial spread of C and C++ appealed strongly to many programmers.
Java is a very different design from the other two languages and appears to have a very different philosophy. It owes much of its initial popularity to the most intense marketing campaign ever mounted for a programming language. From its initial commercial debut onward, Java was marketed as radically different from, and better than, all other languages. Interestingly, Java was marketed to individuals at all organizational levels -- not just to programmers.
I suspect that the root of many of the differences between C/C++ and Java is that AT&T is primarily a user (a consumer) of computers, languages, and tools, whereas Sun is primarily a vendor of such things.
Just to remind people: Both C and C++ were invented in the Computer Science Research Center of Bell Labs in Murray Hill and found their initial serious use within Bell Labs and AT&T. Then, Bell labs was the R&D arm of AT&T. Now, part of Bell Labs is the R&D arm of Lucent and part stayed with AT&T under the name "AT&T Labs."
None of these languages was radically different or dramatically better than other contemporary languages. They were, however, good enough and the beneficiaries of luck and "social" factors such as Unix, low price, marketing (Java only), etc.
Among technical factors, C and C++ benefited from their closeness to machine and absence of artificial restrictions on what can be expressed. That allows low-level systems work to be done in these languages and for the full performance of a machine to be delivered to its users. Java benefited from running in its own virtual machine and from coming with a large set of libraries that decrease the time needed for a programmer to become productive. Unix gave a similar boost to C. In contrast, the C++ world suffers from fragmentation of its huge base of libraries, many of which are proprietary and supplied by competing vendors.
James Gosling: I think that the number one reason is that it's been generally a very pragmatic family of languages. By and large they weren't experiments in language design; they were put together as tools by people who wanted to do something else. C was very largely driven by the writing of the Unix operating system and all the utilities in it, and so a lot of the things that are in C are straight from what it takes to build an efficient operating system, and also what it takes to do that on a machine that only has 32K.
