For you Emacs users that like to edit Inventor files, here's a definition of iv-mode, a major mode for Inventor. [It is a blatant rip-off of the c++ mode that comes with Xemacs.] It handles indentation pretty well. It also works pretty well with VRML files, versions 1 and 2.
And here's a pointer to my personal set-up file for this mode for Inventor and VRML files. It sets up font-lock highlighting (if you're using XEmacs) and different indentation levels for Inventor and VRML (4 spaces for Inventor and 2 for VRML).
pss@sgi.com