via http://gbatemp.net/index.php
Gericom has updated MKDS Course Modifier, the GUI driven Mario Kart DS hacking tool for the PC, to version 2.1.1. See the change log below for what's been added, and be sure to check out the on-going discussion for the download, instructions, and more information about this application.

QUOTE: Change Log 01/22/12
  • Fixed a little bug while importing type5 textures.
  • Lighting in nsbmd viewer.
  • Transparent polygon support in nsbmd viewer.

    2.1
  • NSBTA in NSBMD viewer.
  • Rewritten nkm editor.
  • Rewritten kcl viewer(not complete yet).
  • If you open a carc or narc file inrom you can save it back into it.
  • Better sseq playing.
  • Much better type 5 textures.
  • You can change the texture type.
  • Generate course pictures.
  • Arm9 hacking (only in original rom).
  • Import function in carc/narc.
  • Hex editor (right click the file in carc/narc)
  • Joints in nsbmd viewer.
  • Nsbmd viewer have gray background from now.
  • Better nsbmd viewing. (sometimes problems with textures)
  • Better viewing of truculent textures in nsbmd viewer.
  • (and maybe more what I don't know)

http://gbatemp.net/topic/299444-mkds-course-modifier/