Waitress is meant to be a production-quality pure-Python WSGI server with very acceptable performance. It has no dependencies except ones which live in the Python standard library. It runs on CPython on Unix and Windows under Python 3.7+. It is also known to run on PyPy 3 (python version 3.7+) on UNIX. It supports HTTP/1.0 and HTTP/1.1. Waitress now validates that chunked encoding extensions are valid, and don't contain invalid characters that are not allowed. They are still skipped...