Just add these to your local index to get started on your indexing journey. If you have some more (non-copyrighted) open directories to add, open a PR!
- https://ftp.debian.org/debian/pool/main/d/debian-games/ - Games from the official Debian apt repo
- https://ftp.gnu.org/gnu/ - GNU software
- https://freeware.epsc.wustl.edu/Win and https://freeware.epsc.wustl.edu/Mac - Old freeware for a variety of platforms
- https://ftp.mozilla.org/pub/ - Mozilla software
- http://ftp.lip6.fr/pub/ - A variety of software, including some old versions of Windows and Linux.
- https://ftp.osuosl.org/pub/ - Mirror of free software projects, including LibreOffice, CentOS, and more.
- https://www.chocolate-doom.org/downloads/ - Chocolate Doom, a Doom source port