Massa's little trying-to-be-comprehensive study about the GPL.
(C) Humberto Massa 2004
This essay is hereby licensed to the reader, granting full rights of
modification and redistribution, provided (1) every derived work
maintain my copyright notice, (2) the original title is mentioned in
every derived work and (3) every derived work is distributed under this
same license.
THE THING
Rights granted from an author to an licensee when the former licenses
under the GPL some work to the latter or to a redistributing third
party, who then passes it on to the licensee:
1. making verbatim copy of source code (§ 1, caput, "You may..."),
SUBJECT TO carrying along the copyright notice, disclaimer, and a copy
of the license, ("provided...") SUBJECT TO not imposing any further
restrictions on the recipients' excercise of the rights the license
grants to him (§ 6, "You may not impose...")
2. distributing everything covered by [1] above ("You may copy and
distribute...")
3. charging a fee for the physical copy (§ 1, paragraph, "You may
charge...")
4. offer warranty protection for a fee ("you may at your option...")
5. modifying any portion of the program THUS making a derived work, (§
2, caput, "You may modify..."), SUBJECT TO causing modified files to
carry notices of changing (§ 2, (a), "You must...") AND IF there is an
interactive announcement with copyright notice and/or disclaimer in the
original work, your derived work MUST print the said announcement (§ 2,
(c), "If the modified...")
6. distributing any derived works covered by [5] above, (§ 2, (b), "You
must cause any work...") SUBJECT TO licensing your modifications to all
third parties under the GPL ("to be licensed...")
7. licensing under any license you want parts of your modifications
covered by [5] (and [6]) above (§ 2, 1st paragraph, "If
identifiable..."), THOSE PARTS which can be "reasonably considered
independent and separate works in themselves", i.e., not derived works
from the original work; SUBJECT TO distributing such parts separately
("But when you...")
8. aggregating in the same storage or distribution medium non-derived
works under other, unspecified, licenses (§ 2, 3rd paragraph, "In
addition, mere aggregation...")
9. copy the original work in executable or object code form, (§ 3,
caput, "You may copy..."), SUBJECT TO: accompanying it with the source
(§ 3, (a), "...it with the complete... OR offering to send the source
for a non-profit charge valid for 3 years (§ 3, (b), "...it with a
written...") OR IF you received the program in executable/object code
form AND are redistributing it non-commercially, accompanying it with
the information as to the referred offer you received (§ 3, (c), "...it
with the information...") OR IF the executable/object code is being
distributed by accessing and copying from a determinated place, is
offered access to the source code from the same place (§3, 2nd
paragraph, "If distribution...")
10. apply the terms of [9] to modified/derived works covered by [5] and
[6] (§3, caput, "(or a work based on it, under section 2)")
11. disclaim warranties on your derived works, as they are disclaimed in
the text of the GPL.
ALL THIS RIGHTS ARE SUBJECT TO: no conditions being imposed to the
licensee that contradicts the conditions of the GPL (the SUBJECT TO
clauses here and in [1] to [11] above) or that excuses some of the
conditions (§ 7, caput, "If, as a consequence...")
WHY IS THE REST OF THE GPL NOT IN THE STUDY?
- §§ 1, 2, 3 are covered
- § 4 talks about how the GPL terminates itself
- § 5 explains why and in which circunstances the licensee is accepting
the terms of the license
- § 6 is covered; the license transfer clause is indicated in the
heading of the study items; the "no more restrictions" clause is here
AND IT INVALIDATES LICENSES THAT COMBINE THE GPL WITH MORE
RESTRICTIONS; all works such licensed are undistributable by anyone
but the original copyright holder
- § 7, caput, is covered
- § 7, 1st paragraph is a "balance of section clause"
- § 7, 2nd paragraph and 3rd paragraph are explanations
- § 8 gives the original work copyright holder the ability to add ONLY
ONE TYPE OF RESTRICTION in combination with the GPL: the geographic
restriction, SUBJECT BY there is already a restriction on the
distribution of the work for the part of the restricted countries
- § 9 and paragraphs say you can license your work "GPL version X or
later"
- § 10 explain how to proceed to combine different-licensed works
- §§ 11 and 12 are the warranty disclaimer
QUICK ALGORITHMIC APPROACH TO READING THE GPL AND THIS STUDY:
bool can_i_do(something) {
if( copyright_law_grants_me_the_right_of(something) )
return true;
if( is_in_rights_granted_from_1_to_11_above(something)
&& the_SUBJECT_TO_clauses_are_satisfied_by(something) )
return true;
return false;
}
2004.May.12 @ Brasil, MG, Belo Horizonte
