ISP Page (Backbones, NAP's , etc)

Sean Donelan's "Peering Matrix" message (a couple of weeks ago) has

If I called it a "Peering Matrix" I apolgize, it was an exchange point
connection matrix of a few EXPs I bothered to check. I don't have
information on who is peering with whom at the exchange points. LINX
is one of the few exchange points where a peering matrix is published.