Of all the python > javascript implementations that allow you to run programs in the browser, we chose the skulpt library.
- It works much faster than other libraries,
- it implements many ready-made python modules,
- and skulpt allows you to control the progress of the program, so the learning platform has a debugger.

Skulpt implements python 2. Some of the differences (e.g., print as a function, not an operator) are removed in the python 3 emulation mode used on our learning platform.

As for unsupported python 3 features, students don't reach them while working on the online platform. The project part is implemented on the basis of VSCode, this program supports a full-fledged third version of the Python language.