Why should I care?

There are plenty of alternative Python implementations available. The Python wiki page on that topic (https://wiki.python.org/moin/PythonImplementations) features dozens of different language variants, dialects, or implementations of Python interpreter built with something other than C. Some of them implement only a subset of the core language syntax, features, and built-in extensions, but there are at least a few that are almost fully compatible with CPython. The most important thing to know is that, while some of them are just toy projects or experiments, most of them were created to solve some real problems – problems that were either impossible to solve with CPython or required too much of the developer's effort.

Examples of such problems are as follows:

• Running Python code on embedded systems
• Integration with code written for runtime frameworks, such as Java or .NET, or in different languages
• Running Python code in web browsers

The following sections provide a short description of, subjectively, the most popular and up-to-date choices that are currently available for Python programmers.