The first part is probably easily recognizable, even to non-Catholics, because of such Christmas hymns as Angels We Have Heard on High.
The text of the prayer in Latin:
GLORIA in excelsis Deo et in terra pax hominibus bonae voluntatis.
Laudamus te, benedicimus te, adoramus te, glorificamus te, gratias agimus tibi propter magnam gloriam tuam, Domine Deus, Rex caelestis, Deus Pater omnipotens.
Domine Deus, Agnus Dei, Filius Patris, qui tollis peccata mundi, miserere nobis; qui tollis peccata mundi, suscipe deprecationem nostram. Qui sedes ad dexteram Patris, miserere nobis.
Quoniam tu solus Sanctus, tu solus Dominus, tu solus Altissimus, Iesu Christe, cum Sancto Spiritu: in gloria Dei Patris. Amen.
And the English translation we use in mass:
Glory to God in the highest,Here's a beautiful Gloria from William Byrd, one of my faves!
and peace to his people on earth.
Lord God, heavenly King, almighty God and Father,
we worship you, we give you thanks, we praise you for your glory.
Lord Jesus Christ, only Son of the Father,
Lord God, Lamb of God,
you take away the sin of the world: have mercy on us;
you are seated at the right hand of the Father: receive our prayer.
For you alone are the Holy One, you alone are the Lord,
You alone are the Most High, Jesus Christ,
with the Holy Spirit, in the glory of God the Father. Amen.
And suddenly there was a multitude of the heavenly host with the angel, praising God and saying: "Glory to God in the highest and on earth peace to those on whom his favor rests." (Luke 2:13-14)