The BEAM Book is a comprehensive reference documentation project that describes the internals of the Erlang runtime system and its virtual machine, the BEAM.
The project addresses the lack of authoritative documentation about how the Erlang runtime actually works internally. It takes the form of a collaboratively-written book in AsciiDoc format that covers the architecture and implementation details of ERTS and the BEAM virtual machine. The book is available as a downloadable PDF, an online HTML version, and in printed form, with chapters organized by topic and tracked through completion states ranging from placeholder outlines to finished documentation.
The tool suits developers who need to understand Erlang runtime internals, whether for performance optimization, debugging, contributing to Erlang itself, or building tools that interact with the runtime. It is particularly valuable for those working on Erlang implementations, virtual machine extensions, or deep system-level work. The project explicitly welcomes contributions and frames itself as a collaborative effort rather than a finished product, making it suitable for community-driven improvement.
The project maintains active builds for both PDF and HTML outputs through automated workflows. Contributions are actively solicited through a structured process that tracks chapter completion states and coordinates work via issue tracking. The codebase includes build infrastructure supporting multiple output formats and development environments, with documentation of style conventions and linking practices to ensure consistency across contributions.
