Section 2
You may modify your copy or copies of the Program or any
portion of it, thus forming a work based on the Program, and copy
and distribute such modifications or work under the terms of
Section 1 above, provided that you also meet all of these
conditions:
You must cause the modified files to carry prominent
notices stating that you changed the files and the date of
any change.
You must cause any work that you distribute or
publish, that in whole or in part contains or is derived
from the Program or any part thereof, to be licensed as a
whole at no charge to all third parties under the terms of
this License.
If the modified program normally reads commands
interactively when run, you must cause it, when started
running for such interactive use in the most ordinary way,
to print or display an announcement including an
appropriate copyright notice and a notice that there is no
warranty (or else, saying that you provide a warranty) and
that users may redistribute the program under these
conditions, and telling the user how to view a copy of
this License.
Exception
If the Program itself is interactive but does not
normally print such an announcement, your work based
on the Program is not required to print an
announcement.
These requirements apply to the modified work as a whole.
If identifiable sections of that work are not derived from the
Program, and can be reasonably considered independent and separate
works in themselves, then this License, and its terms, do not
apply to those sections when you distribute them as separate
works. But when you distribute the same sections as part of a
whole which is a work based on the Program, the distribution of
the whole must be on the terms of this License, whose permissions
for other licensees extend to the entire whole, and thus to each
and every part regardless of who wrote it.
Thus, it is not the intent of this section to claim rights
or contest your rights to work written entirely by you; rather,
the intent is to exercise the right to control the distribution of
derivative or collective works based on the Program.
In addition, mere aggregation of another work not based on
the Program with the Program (or with a work based on the Program)
on a volume of a storage or distribution medium does not bring the
other work under the scope of this License.