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

lxml
1.3beta

This version was deleted from PyPI around 2023-12-31. Installing fails with:
$ pip3 install lxml==1.3beta ERROR: Could not find a version that satisfies the requirement lxml==1.3beta
View other deleted versions of lxml

Install through StableBuild

You can install this package from StableBuild's PyPI snapshots from before the version was deleted:
pip3 install \ -i https://YOUR_API_KEY.pypimirror.stablebuild.com/2023-12-29/ \ lxml==1.3beta
Sign up for StableBuild to get an API key (it's free and takes <60 seconds!)

Or, download files manually

And install manually via pip:
lxml-1.3beta.tar.gz (685.5KB)
lxml-1.3beta.win32-py2.3.exe (2.1MB)
lxml-1.3beta.win32-py2.4.exe (2.1MB)
lxml-1.3beta.win32-py2.5.exe (2.1MB)