OpenSmalltalk

OpenSmalltalk is a “cross-platform virtual machine for Squeak, Pharo, Cuis, and Newspeak”. It has many contributors. The person with the most commits is Eliot Miranda.

Many variants of the VM can be built with options such as:

with or without just-in-time (JIT) compilation
green threads (“light-weight processes above a single-threaded VM) or multi-threaded VM (“shares the VM betwwen any number of native threads”)
with or without Spur

Spur provides “a partial read barrier for efficient support of live object-oriented programming.” It is currently used by Squeak, Pharo, and Cuis.
with or without Sista

Sista “adds support for adaptive optimization that does speculative inlining”. As of October 2024 it was still in development.

Obtaining a VM

To obtain an OpenSmalltalk VM:

Clone the repository by entering git clone https://github.com/OpenSmalltalk/opensmalltalk-vm.git

The only branch present on 11/28/2024 was “Cog”.
Perform source file substitutions by entering ./scripts/updateSCCSVersions
Choose between the Stack, Cog, and Sista VMs.

Currently it seems that Cog is preferred.
Choose between the v3 and Spur VMs.

Currently it seems that Spur is preferred.
For ARM-based Macs
- cd to the building/macos64ARMv8/squeak.cog.spur directory.
- Copy the file Squeak.app to the Applications directory.

Building a VM

To install everything needed to build an OpenSmalltalk VM for macOS:

If Xcode.app is not installed, install it.
If the Xcode Command Line Tools are not installed, install them by entering xcode-select --install.
If Homebrew is not installed, install it.
If the cmake command is not installed,i install it by entering brew install cmake.

To build the VM:

cd to the building/macos64ARMv8/squeak.cog.spur directory.
Enter ‘xcodebuild -runFirstLaunch` (not sure about this step)
Enter ’./makespur` (not sure about this step)

This will run for a long time (~10 minutes) and produces a large amount of output. There will be many warnings about issues such as unused variables. I got 39 warnings and 1 error. The error was “call to undeclared function ‘literalBeforeInlineCacheTagAt’”. Where is the generated VM placed?

For more detail, see HowToBuild.

Downloading an Image

Squeak

To download the base image for Squeak, browse Squeak Downloads.

For the latest non-stable image:

Click the link under “Current Trunk Image”.
Scroll to the bottom of the list to see the most recent image.
Click the link for the desired image.
Select the appropriate file for your platform which will be a .dmg, .tar.gz, or .zip file.
Double-click the downloaded file to install/uncompress it.

For the latest stable image:

Click a “Release” link under “Images and Changes”.
Click the “Sources” link under “History” to download the file SqueakV60.sources which must be placed in the same directory as each Squeak .image file.

Running an Image

To run an image, double-click Squeak.app. That will open a dialog that prompts for a .image file. Select one and click the “Open” button.

Alternatively, double-click a Squeak .image file.