Snap in Top 10

The first observation to make is that four of the languages are in both the very first and the latest Top 10. Their names are in bold in the table.

The initial top three languages in the TIOBE Index were Java, C and C++, and in  March 2025 they were in #3, #4 and #2 respectively. From the table it can be seen that none of these three languages have never been outside the top 5 and looking at the long term chart, Java and C were clearly dominant in  #1 and #2 until Python overtook first Java and then C, becoming the firmly established at #1 around August 2023. In the PLDB these languages are in #4, #2 and #5.

It is quite easy to explain why Java and C/C++ dominated and contine to do so. Java is the workhorse in banking and finance and is deelpy rooted. While newer JVM languages such as Scala and Kotlin have come along they haven't really been competitors. C and its close relative C++ are languages that are"close to the machine" and as such underpin programming itself.  

The language that was in the initial Top 10, at #6, and there again in March 2025, at #10, is Delphi which is making a surprise comeback, having been as low as #30. An extension of Pascal, it had been important in academia until Python usurped its role in education. Used in many legacy applications which need to be maintained it has contined to evolve with Delphi 12 released in 2024. However in the PLDB it comes well down the ranking at #137, whereas all the other languages in the table are in its Top 50.

Today's Most Popular Languages

While JavaScript fell just outside the initial TIOBE Top 10, it was at #11 in June 2001 it entered it the following month and was at its highest ever rank of #6 in March 2025. Duing the interim it has on occasion left the Top 10, though only by a small margin as its lowest position of #12 was in October 2014. On TIOBE it has generally been around #9. By contrast job-related rankings, including PLDB's JavaScript comes top and as "the language of the web" I'm always surprised it has so low a position on TIOBE.

I am not at all surprised however that Python is the top programming for TIOBE, despite the fact that it initially it was outside the Top 10, being  #13 on TIOBE in June 2001. This, however, was its lowest ever position, which it occupied until February 2003. The March 2007 chart shows it in #8, a position it had achieved in 2004. Python was in and out of the Top 10 from 2005 to 2018 when it started on its unstoppable rise. Python is a general purpose language, under active development and well supported by libraries that extend its capabilities, especially with regard to data and machine learning. Add to this the fact that it relatively easy to learn and start using, with many beginner's courses available  and these are the factors that explain its current popularity. It ranks #3 on the PLDB.

Departures and Arrivals

PHP, which is at #13 in March 2025, is a language that has been in the TIOBE Top 10 for most of the time, leaving it, possibly for the final time only in 2024. Its initial position in June 2001 was #9, although by August it has dropped two places to #11. Its highest ever #3, achieved in March 2010 when it briefly overtook C++. Its lowest ever was #17, as we reported in April 2024.

PHP is the stalwart server-side web technology and while it has often been under-appreciated, in its developers under-paid, it was and to a large extent still is, essential. It is at #9 on PLDB which seems to be a more realistic position.

The language in our table that left the TIOBE Top 10 most quickly is COBOL It was #10 in June 2001, rose to its highest place ever, #8, in August 2001. Its low point was 2011 when it was in #47 but in March 2025 re-entered the Top 20 at #20, something it has achieved off and on over a chequered history.

COBOL is one of Paul Jansen's "dinosaurs" so why has it reared it's head again? It was devised in 1959, making it the third oldest language in the Test of Time table. As its full name COmmon Business-Oriented Language suggests, it was created to address the need for a standardized programming language that could be used to develop business applications across different mainframe computers and it is the need to keep legacy systems that underpin critical business operations in sectors such as banking, insurance, and healthcare going that means it is still in demand. It is also still evolving with the latest version being COBOL 2023. Its PLDB ranking is 38, which confirms its current vibrancy.

At the start Fortan was at #12, two places below COBOL and in March 2025 it was slightly higher at  #11, having been at #8 in November 2024. Having been as low as #50 in July 2020, Fortran has made a strong comeback in the past couple of years, with one reason being the release in 2023 of a new ISO Fortran definition demonstrating that the language is still evolving. The other being that it still outperforms other languages at number crunching at a time when there is a growing demand for numerical/mathematical computing and the growth of the supercomputer.

Initially released with the full title "The IBM Formula Translating System" shortened to FORTRAN, which was all in caps until Fortan 90,  the language was designed specifically for the IBM 704 by a team led by John Backus and was one of the first compiled computer languages. As the first high-level computer language it influenced many subsequent languages and every single language that compiles an expression owes a debt to Fortran. It ranks #50 on PLDB which seems a bit on the low side.

The other resurgent language is Ada, which started at #15 and  re-entered the Top 20 in March 2025 at #18. Mainly used by the US military and with a focus on code safety, it too had a recent new release, Ada 2023, and is presumably in demand to keep legacy systems going. Its PLDB ranking is 48.