All classes in Glaive require the same experience to advance. This doesn't mean that a mage will get 6th level spells at 760,000 xp tho. All progressive abilities (those having a progression table showing percentages) will gain those abilities earlier or later, depending on how much xp they would have normally required. For instance, a mage may not gain 6th level spells until 13th level.
The advantage of this system is classes which have one very good ability will not be penalised with poor HP's, THAC0, or Character Points. An extreme example of this Knights of Solamnia in Krynn. These require 500,000 xp to advance one level, which means they are left behind the fighters in terms of combat ability, when the reason they pay this amount is the good clerical progression they have.
Level exp 1 0k 2 2k 3 4k 4 8k 5 16k 6 32k 7 62k 8 110k 9 180k 10 275k 11 400k 12 560k 13 760k 14 1000k +250k/level thereafter