I haven't posted much in a while...and I thought I'd post a blog for downgrading.

This is a Guide for how to downgrade your Minecraft to any previous version. *Like Beta 1.5,Minecraft Alpha,Indev,etc.*

Guide:

Get the MCNostalgia downgrading tool from MinecraftForum.(Google it.)

Then make sure you have a fresh minecraft.jar *No mods installed in it.* If it has mods in it all you have to do is delete your bin folder then run the game for a fresh new one or just goto the launcher then goto options then click Force-Update.
*Also before using MCNostalgia make sure your Minecraft is closed.*

Then.....in the MCNostalgia archive you downloaded.*Probably a folder if you don't have 7ZIP or winRAR.*
Run the MCNostalgia.exe then read what it says.Press enter to see all versions you can downgrade to.

Type the number beside the Minecraft version you want then press enter.It will change your minecraft.jar to a previous version.

Then you can have fun playing old-versions of Minecraft.

NOTE: To go back to the regular version.*The most-up to date version.* Just force-update in the launcher or delete your bin folder in the .minecraft folder then log-in to the launcher*

There's also a digiex launcher that lets you play other minecraft versions...though it doesn't change your minecraft.jar so you can play versions without having to change your regular .jar.Un-like MCNostalgia though...there's no Indev...but also un-like MCNostalgia it has Survival Test.