XP Gain

Experience dropped from mobs on the server is not the same as vanilla. The exact amount changes from mob to mob, but generally it's a drastic increase.

Experience gained from other sources (such as furnace cooking, or animal breeding) is also increased from vanilla.

Unlike in vanilla, killing mobs with fall damage or some other ambient environmental factor will still result in them dropping XP. *

* Note: if you're killing mobs this way, the mobs will not drop any money