perlhist Perl history records
d perldelta Perl changes since previous version
-D perl594delta Perl changes in version 5.9.4
+D perl595delta Perl changes in version 5.9.4
+ perl594delta Perl changes in version 5.9.4
perl593delta Perl changes in version 5.9.3
perl592delta Perl changes in version 5.9.2
perl591delta Perl changes in version 5.9.1