This is a bugfix release for

This only fixes one bug: Playing following linking sounds in SMP was causing players to be kicked from the game.

To recap: there is only one download (found at the bottom of this post); This file is the universal install for client and server; it no longer goes in the jar.
Mystcraft goes in the mods folder.

If you are still lost after 0.10, check out Direwolf20′s Mod Spotlight!

Download: [1.5.1] Mystcraft Universal
Check the Mystcraft Forums for updates and the change log.