Choosing the right programming language for a Software Development Kit (SDK) is crucial for driving adoption and providing a positive experience for developers. The most critical factor in selecting languages is understanding who the target audience is and the specific ecosystems they operate within. While trends can provide context, it's essential to prioritize building SDKs in languages that fit seamlessly into their existing workflows. Understanding broader language usage can help identify other languages that could expand the SDK's potential user base. The top languages for SDKs in 2025 include Python, JavaScript/TypeScript, Java/Kotlin, C#, and Go, each with their key industries and characteristics. Developing high-quality, idiomatic SDKs requires significant effort and specialized expertise, but tools like liblab can address this challenge by creating SDKs directly from OpenAPI specs and supporting multiple programming languages. Prioritizing building SDKs in the languages and platforms your developers use is essential for facilitating integration and adoption, ultimately serving as the main connection between an API and developers.