To better assess the growth prospects of programming languages, JetBrains’ 2024 report introduces the JetBrains Language Promise Index, which is based on the growth in usage of the language over the past five years, the stability of this growth, the share of developers intending to adopt the language, and the share of the language’s current users who want to adopt another language.
Based on this formula, the “undisputed leaders” of the JetBrains Language Promise Index are TypeScript, Rust, and Python, JetBrains reported. TypeScript usage has surged from 12% in 2017 to 35% in 2024, while Python usage has grown from 32% in 2017 to 57% in 2024 and Rust usage has grown from 2% in 2018 to 11% in 2024. Java usage, meanwhile, has slipped from 47% in 2017 to 46% in 2024, although it had surged to 54% in 2020.
Despite its gains, TypeScript will not replace JavaScript, according to the report. JavaScript remains one of the most popular and fundamental technologies in the software development industry. Still, TypeScript offers benefits over JavaScript including early error detection during development, improved code quality, compile-time error catching, more reliable refactoring, and native support for ECMAScript 2015 (ES^) modules.