How are doxologies formed for common prayers? I'm not sure of the exact definition, but a doxology seems to be a prayer tagged at the end which consists of some sort of invocation of the Blessed Trinity. 

I'm just wondering if the actual words in a given doxology are important or if in prayer books, like the Book of Common Prayer (for the Liturgy of the Hours) the doxology given is just the most common one used, but shortened for some reason. 


  Glory to the Father and to the Son and to the Holy Spirit, as it was in the beginning, is now and shall be forever


The prayer we teach in Religious Ed. is similar, and the one used in praying the Rosary


  Glory be to the Father and to the Son and to the Holy Spirit, as it was in the beginning is now and shall be forever world without end.


So, this is a three part question. 


Why do we pray a particular version of the 'Glory Be' during the Rosary and another during the Liturgy of the Hours
Is the prayer interchangeable (especially when said in private)
Is the translation likely to resemble the Latin more closely in the future, with the changes to the Mass?
and 3. I guess it has just historical reasons, and it will probably be corrected someday. In most languages, there's just one version of Gloria Patri.
In Liturgy of Hours it should still be Gloria Patri, and if you pray it by yourself, the translation shouldn't be important. On the other hand, it shouldn't be replaced by other, though similar, prayers (but I've seen much bigger tresspasses against liturgical rules and AFAIK it doesn't make the whole prayer useless). In Rosary and other uses, it's even more free.