TIOBE has published its latest Programming Community Index of the world’s most popular programming languages, revealing good growth for Kotlin and a continued dropoff in Java usage.
It is important to note that this index is not about the best programming language or the language in which most lines of code have been written.
The organisation uses search engines and online services like Google Search, Bing Search, Yahoo Search, Wikipedia, Amazon, YouTube and Baidu to compile a monthly index of the top 20 most popular programming languages.
The ratings are based on the number of skilled engineers proficient in a certain language, the number of courses available for that language, and how many third-party vendors use the language.
“The index can be used to check whether your programming skills are still up to date or to make a strategic decision about what programming language should be adopted when starting to build a new software system,” TIOBE explains.
In November 2023, Kotlin gained 0.17% in its index rating, moving it up three positions from #18 to #15.
Since November 2022, it has increased its rating by 0.68%, accounting for over half its total holding of 1.15%.
The table below shows the top 20 most popular programming languages in the world, according to the TIOBE Programming Community Index.
The first wave of Kotlin popularity was in 2017 when Google announced first-class support for Kotlin on Android.
“At that time, Kotlin peaked at almost 1% in the TIOBE index,” the organisation said. “That record has been beaten this month with a current rating of 1.15%.”
TIOBE said that Kotlin was a direct competitor for Java and could potentially compete with the language in areas outside of Android app development.
“Every Java domain has become an opportunity for Kotlin nowadays,” TIOBE said.
TIOBE Software CEO Paul Jansen said he was “pretty sure” that Kotlin would move into the top 10 most popular programming languages.
“Kotlin fits in the modern programming culture of expressive languages that have a strong type system and avoid occurrences of null pointer exceptions by design,” Jansen said.
“If it can become part of the ‘Big 4’ remains a question that is still to be answered.”
C# closing the gap on Java
Kotlin has played a role in the declining popularity of Java in recent years.
In the latest index, Java’s rating dropped from 8.92% to 8.35%, placing it outside the top 3 for a second month.
While the rating of its biggest competitor — C# — also decreased due to the rise in ratings of smaller languages, its drop was much smaller.
As a result, the gap between the two languages’ ratings has narrowed from 1.21% to 0.7%. C# appears to be on the verge of surpassing Java in popularity.
Java was the most popular language on the TIOBE index for several years, only conceding to C in certain months up to the start of 2020.
It once held a share of over 25% of the community’s programming languages.
However, it has seen a drop in popularity after Oracle introduced a paid licence model for the language in 2019.
In stark contrast, Microsoft made C# free and open source after it was previously only available as part of its commercial Visual Studio software.
Android also switched its preferred app development programming language from Java to Kotlin in May 2019 following a licensing spat with Oracle.