Bazel is an open-source build and test tool designed for multi-language, multi-platform software projects that delivers fast, incremental builds by rebuilding only what’s necessary and leveraging advanced local and remote caching, optimized dependency analysis, and parallel execution. It natively supports Java, C++, Go, Android, iOS, and many other languages, scaling seamlessly from small repositories to massive monorepos and complex Continuous Integration environments. Its declarative extension language lets teams add or customize rules for new languages and platforms, tapping into a growing community ecosystem. Bazel offers query capabilities to inspect and understand dependency graphs, comprehensive versioned documentation and release notes, and robust support via GitHub, Slack, and monthly community updates. Trusted by industry leaders like Google, Stripe, and Dropbox to build heavy-duty, mission-critical infrastructure and applications.