Download of StackManager 1.0 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. We recommend checking the downloaded files with any free antivirus. The application belongs to Internet & Network Tools. This free software for Mac OS X was originally designed by High Fidelity Inc.
From the developer:
Stack Manager is a free application that allows you to control and mange server stacks. This app will generate a virtual environment that you can visit on Localhost using the Interface. Clicking the Start button starts all the servers which then load the Domain, the button will soon turn red and you can start working with this panel.
You may want to check out more software for Mac, such as ryc-server, EdBrowser or JanusVR, which might be related to StackManager.