It appears that Cap'n P has recently been edited out of the Wikipedia page on "Comparison of data-serialization formats".
The edit was done in July 25 with the following comment: "clean list of less notable formats":
It also seems the "clean up" was a little sloppy... leaving behind some dangling footnotes to Cap'n P that confused me until I checked the edit history.
In any case, I don't know enough about this topic to judge whether the clean up was justified but I figured I would let you guys know.
Cheers,
Ricardo