[Update: The first time I read the post, my take was that Jeff Atwood took at face value]{style="color: #ff0000;"} the claim that COBOL is by far the most common programming language in the world. [Subsequently, comments have pointed out he was skeptical. But I still read the post as ambivalent to the claim.]{style="color: #ff0000;"} [(FWIW: I've known Jeff for the better part of a decade and he and I are both judges for the Jolt Awards. I'm hardly 'hating on him.') ]{style="color: #ff0000;"}The "statistics" say that there are 220 billion (b for bill-yun) lines of COBOL in production out there.
Bull.
The COBOL vendors have been pumping that number up for two decades (at least). It was "30 billion lines of COBOL can't be wrong," when I was a magazine editor and, for all its verbosity, COBOL is not a language that is prone to cut-and-paste expansion of its codebase. (The only conceivable way that 200BLoC of COBOL have been written in the past two decades.)
Jeff "digs in" and finds a "big" COBOL application: "Read says Columbia Insurance's policy management and claims processing software is 20 years old and has 1 million lines of COBOL code with some 3,000 modifications layered on over the years." That's supposed to be impressive? An insurance company (the classic mainframe industry) has a significant codebase in COBOL? Wow. Well, just 219,999 to go! (And by the way, the specifics of the codebase are curious: not a lot of COBOL codebases started in 1989.)
The great reality check on the prevalence of COBOL was January 1, 2000. A day utterly hyped (never mind the crazy end-of-the-world nuts, the "statistic" was that Y2K software disasters were going to cost more than half a billion dollars in catastrophic damages) and utterly uneventful (the "reality" was ... what was it? Some bus ticket vending machines didn't work).
Is there a lot of COBOL in the world? Sure, but not nearly as much as you probably think. Many legacy systems have been ported to (primarily) Java and run on modern hardware; it's kind of shocking to encounter a "green screen" mainframe system running on blades, but such systems are probably every bit as common as COBOL on Big Iron.
You know what programming language is much, much more popular than visible?
C