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Pharo is a dynamic reflective pure object-oriented language supporting live programming inspired by Smalltalk.


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This repository contains sources of the Pharo language. Pharo is a pure object-oriented programming language and a powerful environment, focused on simplicity and immediate feedback (think IDE and OS rolled into one). Visit us on or Pharo Discord Server

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Pharo screenshot

Download Pharo

To download the Pharo stable version for your platform, please visit:

Virtual machine

This repository contains only sources of the Pharo image. The virtual machine source code is managed in a separate repository:

Automated Builds

This repository is being built on a Jenkins server and uploaded to

The minimal image contains the basic Pharo packages without the graphical user interface. It is useful as a base for server-side applications deployment.

Bootstrapping Pharo from sources

To bootstrap a new Pharo image you need the latest stable version of Pharo. For more information about bootstrapping, refer to guillep/PharoBootstrap.

The bootstrapping can be done on a properly-named branch using the following script:


This will generate and archive images at various stages of the bootstrap process up to the full image in where hhhhhhh is the hash of the current checkout. Additional information on the stages of the bootstrap and how to snapshot during the process are provided as comments in

  • You can set the BUILD_NUMBER environment variable to a unique integer (this is typically used only for the official builds and will default to 0 if not specified).
  • You can set the BOOTSTRAP_ARCH environment variable to either 64 (the default) or 32.
  • You can set the BOOTSTRAP_REPOSITORY and BOOTSTRAP_CACHE environment variables to do the bootstrap outside of the source repository.
  • You can set the BOOTSTRAP_VMTARGET environment variable to make the bootstrap use a virtual machine already present in your system (otherwise it will download it).
  • If you are on a branch that doesn't follow the expected naming convention ('PharoX.Y'), then the script will pick an appropriate default (such as Pharo12.0). To build Pharo12.0 from a custom branch, you need to set BRANCH_NAME=Pharo12 before the bootstrap script is run.

Bootstrapping with Docker

You can also use Docker if you prefer to control the bootstrapping environment completely. The following Dockerfile provides a Docker image with a fresh build. You can repeat the command git pull && ./bootstrap/scripts/ in a container at any time:

# docker build --tag pharo .
# docker run --rm --name pharo -it pharo
FROM ubuntu:22.04
RUN apt-get update && apt-get -y install build-essential git wget zip
RUN git clone /root/pharo
WORKDIR /root/pharo
RUN git pull && ./bootstrap/scripts/
ENTRYPOINT [ "bash" ]

Alternatively, in the root directory of this project (after a git clone), you can set up a Docker volume pointing to the project directory and build from within the Docker container (nice for Windows environments!):

# in the host environment start a Docker container
docker run --rm -it -v $(pwd)/:/pharo --workdir /pharo ubuntu:22.04 bash
# in the container add the required packages and start the bootstrap script
apt-get update && apt-get -y install build-essential git wget zip

File format

This source code repository is exported in Tonel format. In this format, packages are represented as directories and each class is inside a single file.

How to contribute

Pharo is an open source project very friendly to contributions of the users. See the document CONTRIBUTING how you can help to improve Pharo.

Pharo friendly links and organizations