[mr_toad]

> 0.1% of a billion people

Probably more like 0.0001% these days. I doubt 0.1% of websites ever used it.

[barefootliam]

0.02% of public Web pages, apparently, have the XSLT processing instruction in them, and a few more invoke XSLT through JavaScript (no-one really knows how many right now).

It’s likely more heavily used inside corporate and governmental firewalls, but that’s much harder to measure.