Upvote:1
An Official version is available On Line from the Vatican
This link takes you to the compendium of the catechism of the Catholic Church which is hosted at the Vatican's web page. In Appendix A, Common Prayers, the Gloria Patri is rendered with Latin next to English.
English:
Glory be to the Father and to the Son and to the Holy Spirit, as it was in the beginning is now, and ever shall be world without end. Amen.
Latin
Glória Patri et Fílio et Spirítui Sancto. Sicut erat in princípio, et nunc et semper et in sæ´cula sæculórum. Amen.
Given the source, it's about as official as one can ask for.
Note:
In this prayer's case, unlike the Hail Holy Queen, Te Deum, Magnificat, and Benedictus prayers, the Vatican did not break it into "UK English" and "US English" versions. This indicates that they went to some trouble to render it to the best of their ability.
Given the 2011 changes to the Liturgy, in English, to get closer to literal translations from the Latin into the English, there may be a change in time (the RCC moves slowly, when it moves at all) to render that prayer more literally. Since the date for the Compendium seems to be the year 2005, there may be an update coming. Or not.
Upvote:1
As is recounted here, both are considered legitimate translations, although they are typically found in different contexts:
The "will be forever" form is found in most translations when playing the Liturgy of the Hours.
The "world without end" form, is more common (being the older translation) in other contexts. That's the one that was taught when I was in CCD, and in most groups I've been in that pray the Rosary together, that one is almost always used.