At least back then I found it mega complicated, I would have needed to screen the content of the page and find the comments most probably with a RegEx I guess? Then I would need to feed the comment strings I get into a XML parser which would understand namespaces. Then I would go through the DOM of every of those comments to get out the data.<p>Apart from that I do not think you should compare pingback&#x2F;webmention with trackback. The ones are to inform about some mention&#x2F;comment, the other is transporting the content of it. If you want to compare than I would compare microformats&#x2F;open-graph with trackback.