Every month, TIOBE updates its list of the world’s most popular programming languages; and every month, the same languages dominate the top five slots, in descending order: Java, C, C++, C#, and Python. But after years of stagnation in this uppermost tier, TIOBE is sensing a change is underway. “The gap between the big three and the rest is closing quickly,” read the note accompanying TIOBE’s latest data. “But the candidates for the top 3 are losing market share as well, so it is unknown what is going to happen. The general trend is that the pack is getting bigger.” What’s the reason behind this tightening? Technology professionals are using a broader mix of programming languages in order to get the job done. “Applications that are written in a single programming language are getting rarer nowadays,” the note continued. “As a consequence, more and more languages are gaining popularity down the TIOBE index. So exciting times are ahead of us to see what languages will be the winners of the next few years.” TIOBE’s popularity ratings are based on data from a variety of aggregators and search engines, including Google, Wikipedia, YouTube, and Amazon. In order for a language to rank, it must be Turning complete, have its own Wikipedia entry, and earn more than 5,000 hits for +”<language> programming” on Google. For technology professionals, TIOBE’s analysis translates into some advice: learn multiple programming languages. While knowing some combination of Java, C, Python, and JavaScript can no doubt get you through much of your current and future workload, keeping abreast of new and rising languages (such as Swift and R) can make you more adept at everything from mobile-app development to data analytics. When in doubt, keep learning; and keep in mind that, over the long term, even the most popular technologies and languages risk some degree of obsolescence.