Bazel vs Buck: What are the differences?

Bazel and Buck are both build systems commonly used for building software projects. Let's explore the key differences between them.

1. Language support: Bazel has wider language support compared to Buck. Bazel supports multiple programming languages including Java, C++, Python, and more, while Buck is primarily focused on Java and Android development. This broader language support makes Bazel a preferred choice for projects that use a diverse set of languages.

2. Build caching: Bazel has more advanced build caching capabilities compared to Buck. Bazel is designed to leverage a persistent and distributed build caching system, allowing it to cache and reuse build artifacts across different machines and builds. This can greatly improve build times, especially in large-scale projects. Buck also supports build caching, but its caching mechanism is not as robust as Bazel's.

3. Build graph optimization: Bazel has a more sophisticated build graph optimization mechanism compared to Buck. Bazel analyzes the dependencies between build targets and intelligently schedules and parallelizes the build process to optimize for maximum efficiency. It also has a more advanced incremental build feature, which only builds the necessary parts of the project when changes occur. Buck also supports incremental builds, but its optimization capabilities are not as comprehensive as Bazel's.

4. Ecosystem and community: Bazel has a larger and more active ecosystem and community compared to Buck. Bazel is developed and maintained by Google and has been widely adopted by large organizations, resulting in a strong community of users and contributors. This means that Bazel benefits from a larger pool of resources, documentation, and community support. Buck, on the other hand, has a smaller community and may have fewer resources available for support and troubleshooting.

5. Integration with IDEs: Bazel has better integration with Integrated Development Environments (IDEs) compared to Buck. Bazel provides support for popular IDEs such as IntelliJ IDEA and Visual Studio Code, allowing developers to easily navigate code, perform searches, and run tests directly within their IDEs. Buck also supports some IDE integrations, but its support may be more limited compared to Bazel.

6. Maturity and stability: Bazel is generally considered to be more mature and stable compared to Buck. Bazel has been in development for a longer period of time and has undergone extensive testing and refinement by Google and the wider community. This increased maturity and stability can provide more confidence to developers when using Bazel for large-scale projects with complex build requirements. Buck, while still stable, may have a smaller user base and may be perceived as slightly less mature compared to Bazel.

In summary, Bazel, developed by Google, emphasizes hermetic builds and reproducibility, while Buck, created by Facebook, focuses on fast and incremental builds, offering flexibility and performance optimizations.