Back when 1.4.2 was still not released, in the snapshot 12w36a the beacon looked like this:
Looks pretty decent, isn't it? However, Mojang changed the beacon to this:
The goal of this mod is to bring back the old look of beacons, which actually has a nether star in it instead of a glowing diamond block thing.
How do I use it?
Download the version you want and just install it like any other mod. Please remember that resource packs which have a custom beacon texture might affect the mod.
Can I use it in vanilla server?
Yes, you can. The mod only affect the client side.
Can't a resource pack do that?
The nether star has a smooth rotating animation which cannot be done with resource packs.
Does the beacon in this mod looks exactly the same as the 12w36a one?
Not exactly. The obsidian plate is smaller than the old one, and the beam uses the 12w38a one instead of the 12w36a one because it looks better.
12w36a beacon beam:
12w38a beacon beam:
The mod: