Download of Stacksmith 1.0 for Mac was available from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The software lies within Developer Tools, more precisely IDE. We recommend checking the downloaded files with any free antivirus. The actual developer of this free Mac application is Stacksmith.org.
From the developer:
Stacksmith is an open source project aiming to create a modern HyperCard. A software erector kit that allows beginners to quickly pick up programming, and that stays flexible and powerful enough that it can be used as a development environment for professionals.
You may want to check out more Mac applications, such as JBuddy Bot Builder, Pleinpot or PLCEdit, which might be related to Stacksmith.