This week's snapshot has a very simple change log:

Bug fixes!
Especially one big performance bug was found and fixed, but also a lot of smaller ones. 
The release of Minecraft 1.3 is getting closer, but we still need to test more before it's ready.

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INSTALL INTRUCTIONS 


Windows- 

1. Type %appdata% in the search bar 

2. .minecraft/bin

3. Drag/Copy the new minecraft.jar file into /bin folder and replace it.

4. Make a new folder named "server" .minecraft/server in that folder drag/copy the minecraft_server.jar file 

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MAC - 

1. goto Finder/User/Library/Application Support/minecraft 

2. FOLLOW STEPS 2-4 above.