It's a first draft but I've got ScriptCraft working now as a CraftBukkit Plugin. CraftBukkit is a Mojang-blessed Minecraft server implementation. You run CraftBukkit instead of the standard Minecraft Server. CraftBukkit has a fantastic API and adding plugins is as easy as dropping a file into a folder. I've updated the ScriptCraft source on github to include new bukkit plugin source code but if you're impatient or just want to get your hands on the plugin without having to compile or muck about with MCP, you can download the binary here and just drop it in your craftbukkit's plugins folder.