You're looking at StableBuild's Deleted PyPI mirror - where we index all deleted packages from the Python package registry.

penguinboost
0.3.3

This version was deleted from PyPI around 2026-03-03. Installing fails with:
$ pip3 install penguinboost==0.3.3 ERROR: Could not find a version that satisfies the requirement penguinboost==0.3.3