Bazel vs Xcode: What are the differences?

Key differences between Bazel and Xcode:

1. Build System: Bazel uses a distributed and highly scalable build system that allows for faster compilation and better resource utilization by parallelizing the build process across multiple machines. In contrast, Xcode relies on a single machine for its build system, which can lead to slower builds and limited scalability.

2. Language Support: Bazel supports multiple programming languages, including C++, Java, Python, Objective-C, and more, allowing developers to build projects in various languages within the same build system. On the other hand, Xcode primarily focuses on Apple's ecosystem and primarily supports Objective-C and Swift projects.

3. Build Configuration: Bazel utilizes a declarative build configuration model, where developers specify the dependencies and rules in a BUILD file, promoting a modular and flexible structure. Xcode, however, uses a project-based configuration model, where developers configure dependencies and build settings within the Xcode project file, which can sometimes lead to a less modular setup.

4. Platform Independence: Bazel provides better platform independence, allowing developers to build and test their projects on different operating systems, including macOS, Linux, and Windows, using the same build system. Xcode, being primarily designed for macOS and iOS development, limits the ability to build and test projects on non-Apple platforms.

5. Integration with External Tools and Libraries: Bazel offers seamless integration with external tools and libraries, making it easier to incorporate third-party dependencies and utilize other build tools. In contrast, Xcode has a more closed ecosystem and primarily relies on the use of frameworks and libraries provided by Apple.

6. Scalability and Performance: Bazel is known for its scalability, especially in larger projects, as it can handle millions of lines of code efficiently. Xcode, while suitable for most small to medium-sized projects, may experience performance issues and increased build times in more extensive codebases.

In summary, Bazel provides a distributed and scalable build system with broad language support, platform independence, and flexible build configuration, while Xcode focuses primarily on Apple's ecosystem with a project-based configuration and limited platform support, making it more suitable for smaller projects within the Apple ecosystem.