Installation
To install the package, you will need a recent Squeak. I have been using the 6.1-alpha trunk series: that is, the bleeding edge.
Quickstart
- Download a recent Squeak image and VM.
 - Update to at least trunk update number 23336.
 (Installer squeaksource project: 'Actors') install: 'ConfigurationOfActors'- (optional) Run the tests in package 
Actors-Tests. 
Detailed instructions
Download Squeak
Download a recent 6.1-alpha trunk image and VM for your platform.
Update Squeak
Update your image. Execute the following in a workspace:
MCMcmUpdater updateFromServer
Alternatively, click the Squeak icon in the top left of the window, and choose “Update Squeak”:

As of this writing, my updated image is at update number 23336. This
includes all the Kernel changes necessary for supporting the
Actors package.
Install the Actors package
Execute the following in a workspace
(Installer squeaksource project: 'Actors') install: 'ConfigurationOfActors'
Generally, the ConfigurationOfActors package is the latest release
of the package. After it has been loaded, you can optionally update to
the latest development version with
"Optional step: update to the latest development version."
(Installer squeaksource project: 'Actors') install: 'Actors'