What is wxPython? --> python -----------------
wxPython is a cross-platform GUI toolkit for the Python programming language. It allows Python programmers to create programs with a robust, highly functional graphical user interface, simply and easily. It is implemented as a set of Python extension modules that wrap the GUI components of the popular wxWidgets cross platform library, which is written in C++. Supported platforms are Microsoft Windows, Mac OS X and macOS, and Linux or other unix-like systems with GTK2 or GTK3 libraries. In most cases the native widgets are used on each platform to provide a 100% native look and feel for the application.
What is wxPython Phoenix? -------------------------
wxPython's Project Phoenix is a new from-the-ground-up implementation of wxPython, created with the intent of making wxPython “better, stronger, faster than he was before.” In other words, this new implementation is focused on improving speed, maintainability and extensibility of wxPython, as well as removing most of the cruft that had accumulated over the long life of Classic wxPython.
The project has been in development off and on, mostly behind the scenes, for many years. For the past few years automated snapshot builds have been available for those adventurous enough to try it, and many people eventually started using the snapshots in their projects, even for production releases. While there are still some things on the periphery that need to be completed, the core of the new wxPython extension modules which wrap the wxWidgets code has been stable for a long time now.
Due to some things being cleaned up, reorganized, simplified and dehackified wxPython Phoenix is not completely backwards compatible with wxPython Classic. This is intended. In general, however, the API differences tend to be minor and some applications can use Phoenix with slight, or even no modifications. In some other cases the correct way to do things was also available in Classic and it's only the wrong way that has been removed from Phoenix. For more information there is a Migration Guide document available at: https://docs.wxpython.org/MigrationGuide.html
The new wxPython API reference documentation, including all Python-specific additions and customizations, and docs for the wx.lib package, is located at: https://docs.wxpython.org