On a handful of occasions I've brought up the relative performance problem with DateTime -- tonight I had a little time, so I decided I wanted to port DateTime::Locale to XS to start with.
Nothing fancy, it's just a direct wrapper around the data supplied in CLDR, and it's a minute 10% increase, but I suppose it's a start.. Rate XS PP XS 56497/s -- -10% PP 62578/s 11% -- I didn't include the patch in this mail because of naming issues (I needed to change the module names so I can run PurePerl and XS Datetime::Locale in the same script). Do you care to examine the patch? --d