Not Enough Items
Website: http://chickenbones.net/Files/Old_Versions/NEI is a successor to both Too Many Items and Recipe Book. It arose around the same time as Craft Guide when Alexandria and a few others on IRC suggested that Chickenbones merge both Too Many Items and Recipe Book to remove their greatest flaws, ironically too many items, or in the case of recipe book, too many recipies. Too Many Items was great, but the one thing it lacked was an easy way to search and sort your items. When you had a mod like Red Power coming along with 10000 items both TMI and Recipe Book were racking up the pages. Even if you don't want to use NEI for cheating in items, you will likely feel right at home with the Recipe component of the mod.
For Minecraft 1.4.2
1.4.2.1
NotEnoughItems 1.4.2.1.jar
fe568c845536feeb6a46910ba86b9c74af619362584b97d6dd963ab3fd404bfb
1.4.1
NotEnoughItems 1.4.1.jar
837eedce32699ed624dcfe39dd241f3ce6f57ae59e230bb24983b0ca921ea6db
NotEnoughItems-Bukkit 1.4.1.jar
dbd327b620fdd0c793b2ab3bf301ef3836d2fd2666c03d07ea8e7a885912d6cf