Getting started with Plasma

Copyright (C) 2019-2022 Plasma Team
Distributed under CC BY-SA 4.0

Updated: January 2022
Source: on github
Table of Contents

Since we don’t have static builds yet, you’ll need to build Plasma from source. This file contains some instructions on setting up the prerequisites and building Plasma.

Plasma has been tested on Linux, Windows subsystem for Linux 1 and 2 on x86_64.


You will need

  • GCC or Clang

  • GNU Make

  • git

  • Mercury (tested with 20.06)

  • ninja 1.10 or later

  • asciidoc & source-highlight (if you want to build the documentation)

C++ compiler, make and git

Plasma has been tested with clang and gcc. On debian-based systems you can install a suitable compiler and GNU Make with the build-essential package. Install git at the same time.

sudo apt install build-essential git


You’ll need another language, Mercury, since our compiler is written in it. The latest stable version is required, but other versions may also work. Plasma’s CI currently tests with ROTD 2020-05-31. Compiling Mercury from source can take a long time, but if you’re on Debian, Ubuntu or other derivative running on x86_64 then there are some packages! Read on or follow the instructions at

For Ubuntu 20.04, this is what you need to do:

To install Mercury you’ll need to add a new package repository & GPG key. Download and trust Paul’s GPG key:

cd /tmp
sudo apt-key add paul.asc

Create a new file in /etc/apt/sources.list.d, name it mercury.list and paste in it:

deb focal main
deb-src focal main

You may need to substitue focal for another name, see the Mercury debian packages page.

Now we can install:
sudo apt update
sudo apt install mercury-rotd-recommended


To optionally build the documentation, you need to install AsciiDoc and source-highlight:

sudo apt install asciidoc source-highlight

Beware, this is a very large installation, on a default Ubuntu installation this amounts to over 1 GB of space and a download of over 300MB. If AsciiDoc is not installed, documentation will not be built.


Plasma’s build tool plzbuild needs least version 1.10 of the ninja build tool.

Ubuntu 20.04 has a suitable package.

sudo apt install ninja-build

Or install it yourself from a binary download:

Or run these commands to install ninja 1.10.2 on your x86_64 Linux system:

cd /tmp
sudo cp ninja /usr/local/bin/


If you want to run Plasma in a Docker container, the Dockerfile provided in scripts/docker is available, It is also build and available on docker hub.


Now it’s time to clone the plasma repo:

git clone

If you want or need to, you can configure Plasma’s build settings by copying to and editing it. It contains some documentation for the build options. These include which C compiler to use, and compilation flags. The default build is reasonable if you have gcc. You may need to set the PREFIX variable to your desired installation directory, The Plasma compiler and other tools will be installed to $PREFIX/bin/, you will need to arrange for that to be in your shell interpreter’s path (bug #325 will remove this requirement).

Then run make and it will build you the plasma compiler (src/plzc) and the runtime (runtime/plzrun). Set MAKEFLAGS to build the C++ code in parallel, or set it in your ~/.bashrc.


The make test command will execute the test suite. Be sure to take a look at the example programs in examples/.

make install will install the Plasma tools into $PREFIX/bin/.

Hello world

In a new directory create a BUILD.plz project file, it should contain:

type = program
modules = [ Hello ]

Create a hello.p file to contain the Hello module, it should contain:

module Hello

func hello() uses IO -> Int {
    print!("Hello world\n")

    return 0

Then use the plzbuild program to build the program:

$ plzbuild

This will create a hello.pz file in the current directory containing the program’s bytecode. Run it with:

$ plzrun hello.pz
Hello world

Getting help

If you’re stuck and the Documentation doesn’t contain the answer or clue you need or you’re struggling to find it. Please ask for help. The Contact page of the website lists all the ways you can get in touch. In particular the Plasma Help mailing list and Discord server are the best resources for help.

For bugs or missing information please file a bug.


If you want to write some Plasma programs and you use vim. You may wish to use the vim editor support.