--- layout: documentation title: Custom Rules --- # Custom rules Skylark is the name of the extension mechanism in Bazel. It lets you write [custom build rules](rules.html) as well as compose existing ones into [macros](macros.html). ## Getting started Read the [concepts](concepts.md) behind Skylark and try the [cookbook examples](cookbook.md). To go further, read about the [standard library](lib/globals.html).