THthe_arun·Jun 4, 2025
Here is the link to the git repo - https://github.com/happi/theBeamBook
In Why I wrote the BEAM bookhappi
theBeamBook
Erlang2017–2025
happi / theBeamBook
theBeamBook
A description of the Erlang Runtime System ERTS and the virtual Machine BEAM.
12Distinct people
14Mentions
0Explicit recommenders
4.1KGitHub stars
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What it is
A description of the Erlang Runtime System ERTS and the virtual Machine BEAM.
GitHub
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This week on Hacker News
Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 5:04:57 PM UTC.
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Mentions over time
HN mentions by year14 dated mentions
Observed mentions: 2017-04-07 17:58:34 UTC to 2025-06-04 14:00:03 UTC.
Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.
View mention counts and date ranges
| Period | Start (UTC) | End (exclusive, UTC) | Mentions | Submissions | Comments |
|---|---|---|---|---|---|
| 2017 | 2017-01-01 00:00:00 UTC | 2018-01-01 00:00:00 UTC | 3 | 1 | 2 |
| 2018 | 2018-01-01 00:00:00 UTC | 2019-01-01 00:00:00 UTC | 2 | 0 | 2 |
| 2019 | 2019-01-01 00:00:00 UTC | 2020-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2020 | 2020-01-01 00:00:00 UTC | 2021-01-01 00:00:00 UTC | 3 | 0 | 3 |
| 2021 | 2021-01-01 00:00:00 UTC | 2022-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2022 | 2022-01-01 00:00:00 UTC | 2023-01-01 00:00:00 UTC | 1 | 0 | 1 |
| 2023 | 2023-01-01 00:00:00 UTC | 2024-01-01 00:00:00 UTC | 3 | 0 | 3 |
| 2024 | 2024-01-01 00:00:00 UTC | 2025-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2025 | 2025-01-01 00:00:00 UTC | 2026-01-01 00:00:00 UTC | 2 | 1 | 1 |
What Hacker News says
14 sourcesThe Beam Book: Understanding the Erlang Runtime System (2015)
3 points · Open discussionDive into the BEAM VM.
https://github.com/happi/theBeamBook
In Ask HN: Programming Courses for Experienced Coders?It's my understanding the state of the art in observing JVM-based applications is a combination of using thread dumps, gc logs, thread activity visualizations. Thread dumps give us a snapshot of the the name of the thread, its current running state (waiting, blocked, etc), and the stacktrace of the work its currently doing. GC logs give you a record of when and how much garbage was collected and Thread activity visualizations show you the timeline of thread moving between different running states.
The BEAM gives you the ability to see the bottlenecks in your system, via the REPL (in real time!)
It has world-class introspection built in that gives you the power to observe and manipulate your running application through a REPL.
The BEAM has hundreds of features like this, because the BEAM is more of an OS than and VM.
I get it, you're a JVM
Read the rest
expert, but the BEAM is more than a check list of optimizations that on paper the JVM can do.
I strongly suggest, before the next time you comment on an BEAM VM vs.JVM debate, please consider watching https://www.youtube.com/watch?v=JvBT4XBdoUE, "The Soul of Erlang and Elixir • Sasa Juric • GOTO 2019"
and reading https://github.com/happi/theBeamBook " an attempt to document the internals of the Erlang runtime system and the Erlang virtual machine known as the BEAM."
Best of luck!
I don't know Python or Rust well, but I think this is the problem:
https://betterprogramming.pub/the-dangers-of-async-in-python...
And this is how some people are solving it:
https://async.rs/blog/stop-worrying-about-blocking-the-new-a...
This is how it works in BEAM:
https://github.com/happi/theBeamBook/blob/master/chapters/sc...
The commonality is to limit execution time and yield (preempt) so something else can run too.
In Erlang's not about lightweight processes and message passingit does. values are immutable in the BEAM, not at language level.
The impact of bugs is minimized by compartmentalization. This is done from the lowest level where each data structure is separate and immutable [1]
But you can simulate mutability with stateful processes.
Directly from Joe Armstrong: https://joearms.github.io/published/2013-11-21-My-favorite-e...
[1] https://github.com/happi/theBeamBook/blob/3971e8e2d09e367670...
In Lunatic is an Erlang-inspired runtime for WebAssemblyThe beam book:
https://github.com/happi/theBeamBook
In The BEAM Has Spoiled MePDFs of the beam book available here: https://github.com/happi/theBeamBook/releases
In The BEAM Book (2017)You can download a PDF version from here: https://github.com/happi/theBeamBook/releases
In The Erlang Runtime SystemDon't forget about https://github.com/happi/theBeamBook
In What Erlang Taught Me About Distributed SystemsIt was a cool experiment but I think currently it's deprecated? The presentation slides are very nice and detail and explain a lot of internals.
For more details about the internals of BEAM VM can check out this open source book: https://github.com/happi/theBeamBook
(Online rendered version: https://happi.github.io/theBeamBook/)
In The Halfword Heap Emulator (2011) [pdf]https://github.com/happi/theBeamBook for the VM
http://erlang-in-anger.com/ for introspecting it in production
In How Discord Scaled Elixir to 5M Concurrent UsersThe BEAM Book – A Description of the Erlang RTS and the Virtual Machine BEAM
336 points · Open discussion