Dennis Ritchie, inventor of the C programming language, who died in 2011. Wikimedia Commons The TIOBE Index, a highly-regarded resource for ranking the popularity of programming languages, is a great place to figure out the skills you should learn if you want a career in technology.

By the same token, the TIOBE Index is also a great way to keep your fingers on the pulse of the programming world, as upstarts like Google's Go and Apple's Swift languages make steady gains, pushing old-timer heavyweights like COBOL and Fortran even further down the list.

Now, judging from the August update to the TIOBE Index, it looks like C — the legendary programming language invented in 1972 and still widely used — is showing signs of being left behind as the bulk of new software development gets done on the web and on the smartphone.

"The C programming language has a score of 11.303%, which is its lowest score ever since we started the TIOBE index back in 2001," writes Paul Jansen, who manages the TIOBE Index, in a preface to the August listings.

Overall, C is still doing pretty well. By TIOBE's reckoning, it's still the second most popular programming language in the world, behind only Java, which is widely used in both Android apps and in business software development.

But, by TIOBE's reckoning, this could be a sign of things to come, with C a " bit stuck" amid larger changes to the technology landscape.

C, evolved

Over the years, Java has evolved — originally intended as an operating system for smart televisions, it eventually became massively popular for its rock-solid stability, making it a go-to programming language even during the emergence of the smartphone era.

Meanwhile, C has stayed largely the same, not least because the community of volunteer developers who shepherd the language have focused squarely on performance, rather than adding new features. And so, while C is still being actively developed, it's possible that programmers are finding it less and less suitable for their day-to-day projects as time goes on and computing keeps changing.

"The C Programming Language," the legendary guide to learning the language. Flickr

And C++, an offshoot of C championed by the likes of Microsoft and Intel, already represents the changes that C would have to make to stay relevant. As the TIOBE Index notes, if C put in those C++ features, it would basically just be...C++, which is to say, redundant.

Finally, the TIOBE Index notes that unlike most other major programming languages, C doesn't currently have a major corporate sponsor. Oracle makes a lot of money from Java; Apple pushes both Swift and Objective-C for building iPhone apps. But no big tech company is getting on stage and pushing C as the future of development. So C's problems could be marketing as much as anything.

This is all extrapolated from one month of data, and it's possible that next month, C will have a massive comeback to top the charts. Regardless, this raises fascinating questions about the future of one of the oldest programming languages that's still widely used.