PIPs gave every broadcast a permanent address — not a listings blurb that vanished after transmission, but a real page, with structured metadata, that would still resolve years later. It sounds obvious now. In 2005, most of the BBC's own schedule barely existed as addressable data at all.
The project rolled out first across Radio 3 and Radio 4, and became one of the clearest proofs of an idea I kept coming back to in talks that year: design the data first, and the pages follow.