Download of JSTerminal 1.9 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 actual developer of this free software for Mac is Steel Wheels Project. The software lies within Developer Tools, more precisely Webmaster Tools.
From the developer:
JSTerminal is a GUI application development tool based on the JavaScript. It is a terminal application designed to execute JavaScript shell. You can implement the shell script by JavaScript syntax. The built-in libraries help to implement the JavaScript program. This application can be used for rapid GUI application development.
You may want to check out more software for Mac, such as RAGE Domainer, ModelBaker or iGooMap, which might be similar to JSTerminal.