Create a standardised listing format/file.
Foundries can then host this on their own site at a consistent location for easy indexing by other parties.
There are a myriad of typefaces out there, but outside of monolithic websites like Google fonts and Typekit it can be hard to find them. trackerfr.ee aims to improve the visibility of these foundries but it doesn't surface any of the typefaces available from each foundry. #8
If you were going to create a single index which includes all of this information it will over time become increasing irrelevant. The ideal solution would be for foundries to own and manage updates on their own listing.
There's a rich history of projects which have been created in this way:
Be great to hear your thoughts about how best to structure this document.
Either open an issue here or get in touch via twitter