I spoke to Ton Rosendaal on IRC.

These files aren't in any recent releases, are from 3-5 year old files.  They aren't in SVN trunk either, and haven't been for years.

Apparently they're from the corporate days of NaN, but they've been cleaned out a while ago from modern blender releases.

I found this in the following 4 files:

blender_2.46+dfsg.orig.tar.gz/blender_2.46+dfsg.orig.tar/blender-2.46.orig/release/windows/ installer/02.copyright.txt

blender_2.46+dfsg.orig.tar.gz/blender_2.46+dfsg.orig.tar/blender-2.46.orig/release/windows/ publ_installer/02.copyright.txt

blender_2.49.2~dfsg.orig.tar.gz/blender_2.49.2~dfsg.orig.tar/blender-2.49b.orig/release/windows/publ_installer/02.copyright.txt

blender_2.49.2~dfsg.orig.tar.gz/blender_2.49.2~dfsg.orig.tar/blender-2.49b.orig/release/windows/installer/02.copyright.txt

First, in section 1: "Subject to the provisions of this License Agreement, NaN grants You a limited, non-exclusive, personal, non-sublicenseable, non-transferable, revocable license to use the Software at any computer You own or use."

I see that the license is revocable. When compared to the FSF's definition, "In order for these freedoms to be real, they must be permanent and irrevocable as long as you do nothing wrong; if the developer of the software has the power to revoke the license, or retroactively change its terms, without your doing anything wrong to give cause, the software is not free."

Second, in point #2, you can't "(b) modify, decompile, disassemble or reverse-engineer the Software; (c) sublicense, rent, lease, lend, assign or otherwise transfer rights to the Software." Being able to modify the software is an important freedom.

Finally, in point #3: "You are hereby granted permission to copy and distribute the Software without written agreement from NaN, only for non-commercial purposes. Distributing the Software within a restricted non-public environment, such as using a local network in a company or a local network of a university, is considered a 'non-commercial purpose'. This entire License Agreement must appear in and/or accompany all copies of the Software. Distributing the Software 'bundled' in with ANY product is considered to be a 'commercial purpose'."

The problem with that one is that a free program must be available for commercial use, commercial development, and commercial distribution.