Export plugin for anim8or, allows you to select "Orbiter mesh" as export format, when exporting a object. Only known limitation is that this script does only support single-material meshes.
If the output does have any bugs, please feel free to report them in the Orbiter Forum Thread
Please do also report it, if the colors of the object in anim8or and in orbiter have severe differences. Both use different lighting models, but i would prefer "What you see is what you get."
061209: Write compatible material names, write exporter version hint.
071205: Fixed duplicated mesh groups when materials of the same name appear in both global and local material lists.