Pharo is described as 'pure object-oriented programming language and a powerful environment, focused on simplicity and immediate feedback (think IDE and OS rolled into one)' and is an app in the Development category. There are nine alternatives to Pharo for a variety of platforms, including Mac, Windows, Linux, Online / Web-based and BSD. The best alternative is Python, which is both free and Open Source. Other great apps like Pharo are F# (programming language) (Free, Open Source), React Studio (Freemium), Dolphin Smalltalk (Free, Open Source) and Squeak (Free, Open Source).
React Studio lets you create components either visually or in code, then use them interchangeably in your designs. Customize your components with advanced property UIs and dynamic previews in the editing canvas.
Dolphin is a complete development IDE for Smalltalk targeted specifically at Microsoft Windows. It is capable of creating standalone GUI and console executables that will run on any version of Windows from XP up to the current Windows 10.
HaverOnCuis – for short Haver – provides an opensmalltalkvm based Smalltalk with modules. Haver’s module semantics are inspired by Python’s modules and, to a greater extent, by Scheme’s module semantics.