perlhist Perl history records
d perldelta Perl changes since previous version
D perl5110delta Perl changes in version 5.11.0
+ perl5101delta Perl changes in version 5.10.1
perl5100delta Perl changes in version 5.10.0
perl595delta Perl changes in version 5.9.5
perl594delta Perl changes in version 5.9.4