Yes there is. Its a mod that allows you to back your beta.For example, if you have 1.8.1, you will back it to 1.7.1.
MCdowngrader
You can play Minecraft Classic for free in a browser, at the Minecraft webpage.
There is no way to get the full version of minecraft for free, but you can play Minecraft Classic for free.
If you, by downgrading, mean changing to an older version, then no, you can't. wrong! You can you must have a backup/copy of the old .minecraft in your roaming appdata folder. just take old one and put in there In fact... there is an easier process There is a tool called MCNostalgia which can downgrade your versions of Minecraft. For example, if you don't like some new update (and I kinda do), you can downgrade Minecraft to that version. It currently supports all the way back to Indev (February 2010).
I have never heard any way to downgrade software.
you can play minecraft classic in browser in minecraft.net
No, but you can play on classic single player and if you have a account you can play on multiplayer classic
Their operation doesn't change in any way - they work the same way on a downgrade as they do on flat ground. Now the manner in which they're used will change - occasional snub braking will be used to regulate speed on the downgrade.
There is no way to legally play the full version of Minecraft for free. But an issue of a Magazine called PC Gamer had a free demo of an older version. Also, you can play the Classic version for free at Minecraft.Net
There is no way you can downgrade a PSP-300 or PSPgo at the moment.
Same way you get minecraft on any computer download it.
No, Pandora Batteries (the only known way to downgrade PSPs) do not work with the PSP-3000, and, as such, you can not downgrade it.