I like updates, Infact I love them, i don't care what they add, sheepzombiemen!I just like new features, i play snapshots more than the acutal game versions, my favourite 1.4 feature is anvils
Ugh I get annoyed when people ask this question, if you think you can do this from someone linking you to a mod making application, you will probably never make a mod.
Step one Learn Java which will take about I don't know, a month to a year? it depends. Step two Open class files with a Java script editor or decompile the jar first. Step three If you do not understand my words, you will probably never make a mod, sorry.
so all in all their isn't really a program besides the MCP thing to help you make mods. Sorry to disappoint you!