The pangram for the Irish language in pango-language-sample-table.h is inappropriate because...

1. it used dotted characters which aren’t used in Modern Irish and aren’t present in many fonts. When character substitution occurs this looks really ugly!

A modern rendering would be "D'fhuascail Íosa Úrmhac na hÓighe Beannaithe pór Éabha agus Ádhaimh", but this doesn’t help with my second objection

2. this is an unnecessarily religious text to be using for a font sample (Jesus, Son of the blessed Virgin, redeemed the seed of Eve and Adam).

I would suggest changing it to...

Chuaigh bé mhórshách le dlúthspád fíorfhinn trí hata mo dhea-phorcáin bhig.

“A maiden of large appetite with an intensely white, dense spade went through the hat of my good little porker.”

Windows uses...

Ógánaigh mar Éava agus Úna as Port Árann a d'fhuadaigh báid na nÍoslannach fadó.

“Young men like Eve and Una from Port Árann fled from the Icelander’s boats long ago.”

After a bit of searching, this one actually appears in a thread I started on Gaelic-L in 2001, so it’s probably not MS property.

I’ve not be able to find out what (if anything) Apple use. Despite using Ireland as a tax haven, they don’t seem to have great support for Irish.