Modern agents can be built in various languages, not just Python, but many frameworks assume a Python-only stack. Google's Agent Development Kit (ADK) aims to eliminate this by supporting Python, Go, TypeScript, Java, and Kotlin. Each ADK version is tailored for its runtime while sharing a unified architecture and interoperability via open protocols. The Model Context Protocol (MCP) client in every language allows custom tools to be called universally. For multi-agent systems, the Agent2Agent (A2A) protocol enables communication between agents written in different languages. Getting started involves a one-time setup and scaffolding a project with deployment configurations. The ADK offers distinct advantages for each language, from Python's broad integrations and evaluation tooling to Go's production efficiency and concurrency. TypeScript leverages Zod for type safety and can run directly in the browser. Java integrates with existing Maven, Gradle, and Spring Boot ecosystems. Kotlin prioritizes build-time safety with its KSP compiler plugin, enabling on-device Android agent development. The ADK's multi-language support allows organizations to select the best language for each component without compromise.