GHM — GNU Hackers' Meetings



My virtual machine is faster than yours

Speaker: Luca Saiu

While I was working at making GNU epsilon faster in bootstrapping and interactive use I wrote a fast direct-threaded engine. Disappointed by the modest speedup (4-6x) I attempted something more radical which eventually blossomed into an independent sub-project, completely independent from epsilon.

The talk will show a succession of increasingly sophisticated approaches to accelerate virtual machines, from AST interpretation to threaded code (both stack- and register-based) and beyond, including techniques to reduce overhead from dispatching, VM register access and literal fetching; the final iteration essentially constitutes a JIT. I will give credit where credit is due: most of the techniques shown are already published, but at least one crucial bit is, as far as I see, original.

My new virtual machine generator accepts as input a high-level instruction specification including C code, and generates a fast VM. The system is easy to port: very little assembly code is needed, and even that only serves to enable optional optimizations. I plan to make this new system an independent GNU project. Feedback is welcomed.

The talk will be highly technical. It will assume familiarity with C and at least some ability to read assembly. GForth will be used in a few examples, but familiarity with Forth is not required.

Guix, GuixSD, and getting to one point o

Speaker: Ludovic Court├Ęs

What's up with Guix? As in previous years, I will give an update on Guix and GuixSD, talk about recent developments and nifty hacks. I will focus on the remaining items that will lead us to 1.0 in the coming months.

Libreroot - Liberating Buildroot

Speaker: Tobias Platen

Libreroot is a fully free embedded GNU/Linux distro based on Buildroot ( I removes all non-free packages and replaces the Linux kernel with GNU Linux-Libre. Currently supported targets are the Thinkpad X200 and the BeagleBone Black. Libreroot contains an up to date cross-gcc that supports many architectures including ARM and X86. It can be installed on a Long-Time support GNU/Linux distro such as Trisquel and can be used to cross compile a custom kernel or device tree for a ARM Parabola GNU/Linux system.

Supporting multiple bootloaders in GNU GuixSD

Speaker: Mathieu Othacehe

  • Refactoring Guix to support multiple bootloaders.
  • Easy bootloader switching, flexibility, testing : what are the many advantages of GuixSD approach ?
  • Demo : adding a new bootloader in GuixSD.

The GNU Behistun Package

Speaker: Christopher Dimech

GNU Behistun consists of software and utilities for geological and geophysical modeling and mapping of internal structures and dynamics. The talk will describe in detail the mathematics of imaging for geophysical and astrophysical applications, applications to disaster assessment, monitoring and early warning and the difficulties associated with these endeavours.

Information about related work and collaborations will also be discussed, as well as possible applications to medical imaging.

Using Potluck to break the Guile stalemate

Speaker: Alex Sassmannshausen

How do we share Guile libraries in a convenient form? Perl has CPAN, Emacs has MELPA. What do we use for Guile? The indomitable Andy Wingo proposed Potluck during the last year. An extension to the Guix package manager which might allow us to share Guile only libraries & applications in a convenient and fast way.

In this presentation I aim to share my experiences with Potluck and thus perhaps stimulate the ongoing discussion of this problem.

Introducing GNU Spread Sheet Widget

Speaker: John Darrington

GNU Spread Sheet Widget is a recent GNU project to create a library providing a Gtk+ widget for use by anyone who wishes to present data in a manner familiar to users of popular spread sheet programs. Parameters of the project include O(1) in both time and space, compatability with modern user interfaces and maintainability of the code.

The Future of the GNU Hackers Meetings

Speaker: John Darrington

The GNU Hackers Meetings have been happening for approximately 10 years. Do we want to continue the tradition? How should we organise future meeetings? Who should organise them? Where should they take place? What should happen in the meetings?

Lightning talks

An open mic to present hare-brain schemes, recent hacks or tales of daring do! Want to present something in over the course of about 5 minutes and have a little space for discussion? Sign up to give a lightning talk during the meeting!

Still available!

Have an awesome proposal for a talk? Contact me,, or sign up to give a talk during the meeting!


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