How do I add Mods to a Minecraft SMP Server?

For a mod to work in multiplayer, the author needs to create a SMP version. The most common way is through bukkit.

However if a mod adds new items, like the two examples you have given, playing SMP with it will require both a server mod and client mod to work together. This usually means the same developer or team needs to make both. If they don't provide both yet add new items, the mod is likely single player only.

For combining several of these mods, they all need to use compatible methods of adding themselves. If one is a bukkit mod while the other is its own mod that conflicts with bukkit you're usually out of luck.

I've gotten it to work on a Bukkit server partially. FalseBook, MobRider and Essentials will NOT accept the mod, however. They will continuously send out errors on: BLOCK_PLACE, BLOCK_REMOVE, PLAYER_INTERACT and PLAYER_ANIMATION. Apart from that, new items ARE craftable, placeable (although this will give the before mentioned errors), and useable, as are the planes.

In this link, you will find a page where you can download an appropriate mod loader for SMP (works, I have personally tested it), a different version of Flan's Planes designed for Bukkit and other mods. Link: http://www.minecraftforum.net/topic/382599-173-modloadermp-for-craftbukkit-and-canary/

If anyone knows a way to fix/patch the errors mentioned above (more details if requested) Planes mod would work succesfully and I would be very grateful.