It is yes, but the boot loader comes with certain
privileges that cannot be taken away from you by restrictions enforced in other licenses, such as the Software License Agreement for Mac OS X.
What I was trying to address here, is that modifications to the boot loader, and thus making a derivative work, is not an issue. Not when you follow certain
rules. Here's why:
"
H. Certain components of the Apple Software, and third party open source programs included with the Apple Software, have been or may be made available by Apple on its Open Source web site (http://www.opensource.apple.com/) (collectively the "Open-Sourced Components"). You may modify or replace only these Open-Sourced Components; provided that: (i) the resultant modified Apple Software is used, in place of the unmodified Apple Software, on a single Apple- branded computer; and (ii) you otherwise comply with the terms of this License and any applicable licensing terms governing use of the Open-Sourced Components. Apple is not obligated to provide any updates, maintenance, warranty, technical or other support, or services for the resultant modified Apple Software"
And thus the only problem is installation on a non-Apple branded computer; You are free to replace the boot loader on your Mac computer.
Note: This: "
on a single Apple- branded computer" does not apply to the Open Source parts.