[Sharp_Enderman]

Notice the bit about "minecraft.net" in the URL. I'm not posting a pirating site or anything. This is just another facet of the beloved minecraft.net where all of your dreams come true. (Going a bit off topic now, but this is just another completely legitimate [and legal] method of downgrading your jar.)

EDIT: If you really, really want to waste some of your time on me, you can bop me upside the head whilst you show me that I'm entirely in the wrong by posting said link.
Also the quote you posted from twitter has nothing to do with the link I've posted, mate.

EDIT #2: Doing yet another edit just to save the thread from more of my apparent idiocy. Back to what I was going to say. I read everything in your link to twitter and still don't see anything about posting a link to an older minecraft.jar that's located on minecraft.net's database (I apologize if I'm entirely incorrect in assuming this which would render everything I've said void) via the URL "http://assets.minecraft.net".

[Ninjalo]

Notice the bit about "minecraft.net" in the URL. I'm not posting a pirating site or anything. This is just another facet of the beloved minecraft.net where all of your dreams come true. (Going a bit off topic now, but this is just another completely legitimate [and legal] method of downgrading your jar.)

EDIT: If you really, really want to waste some of your time on me, you can bop me upside the head whilst you show me that I'm entirely in the wrong by posting said link.

http://notch.tumblr.com/post/1121596044 ... racy-works

Yet; at the same time
#Trollnotch
https://twitter.com/notch/status/157261795139125248

[Intelli]

Y u no use http://assets.minecraft.net/1_4_2/minecraft.jar? Heresy.

This / it's perfectly legal (directly from Minecraft.net, not a cracked version)

[Supah_Dupah_Allyupah]

Also, 7zip. Freeeeeeeeee.

[shaddowdemon]

If anything, I would say the actual program linked here is more illegal than just downloading the jar directly.

I looked at the source code, and what I got out of it is that it "diff"s the version. This process takes a binary file vs another binary file and stores the differences between them in another file. So it's basically taking their released version, stripping out parts of it, and redistributing those parts. These scraps of the original release are downloaded from here: http://mcn.sonicrules.org/patches/

So, they are distributing portions of the released binaries instead of the full version. I would say that downloading the full version from Mojang is much more legal than downloading sliced up versions from a third party.

Also, if you want to be technical, I would say that all mods technically violate the copyright also. What is done with all mods: The release version from Mojang is decompiled. It is then patched up to make it more readable. Then modders edit this source code to add hooks and such to catch events, then redistribute their created files with the edited recompiled source files. So in the end, modders reverse engineer, edit, and redistribute Mojang's code.

[Ninjalo]

Y u no use http://assets.minecraft.net/1_4_2/minecraft.jar? Heresy.

This / it's perfectly legal (directly from Minecraft.net, not a cracked version)

Yep. I dug deeper and found that Mojang allows downloads from their servers.

It's not illegal if you download it from Mojang