After looking at the pod for perlxs (in the 5.14.2 release)
I tried to change the url to get the perlapi pod
and got a 404.
The release pages shows perlapi but ilnks to https://metacpan.org/module/FLORA/perl-5.14.2/autodoc.pl
which has a pod error (and not the pod i was looking for).
perlapi is not shown on the release page for 5.16.1
but i can get it on my local machine via perldoc (so it appears to still exist).
perlapi is built when perl is built which makes it dependent on the installed perl version/distro/etc