I prefer to do things manually - I've got jar files going back to something like 1.6 (both modded and unmodded) and I had more, but I lost them in a hard drive failure. No, the thing is that I haven't been interested in 1.3 (or, in fact, any vanilla Minecraft update) - it's only the mods that I care about. Perhaps more to the point, I've just found out that things are going to be extremely busy this week and probably won't get a chance to even look at coding until the weekend. Updates are going to have to wait, I'm afraid.
Also, I run Linux, so that particular link wouldn't be much use to me
Multi MC works on linux (Or you could use Wine, But im not judging)
P.S.-Dont mind the link i just was making it so you dont have to scroll!