Document ID: ./input/supremecourt_opinions/opinions/20pdf/18-956_d18f.pdf
Page Number: 39

Cite as:  593 U. S. ____ (2021) 

35 

Opinion of the Court 

Lexmark Int’l, 387 F. 3d, at 544 (noting that where a subse-
quent user copied a computer program to foster functional-
ity, it was not exploiting the programs “commercial value 
as  a  copyrighted  work”  (emphasis  in  original)).  After  all, 
“copyright supplies the economic incentive to [both] create
and disseminate ideas,” Harper & Row, 471 U. S., at 558, 
and the reimplementation of a user interface allows crea-
tive new computer code to more easily enter the market.

The uncertain nature of Sun’s ability to compete in An-
droid’s market place, the sources of its lost revenue, and the
risk of creativity-related harms to the public, when taken
together, convince that this fourth factor—market effects—
also weighs in favor of fair use. 

* 

* 

* 
The  fact  that  computer  programs  are  primarily  func-
tional makes it difficult to apply traditional copyright con-
cepts in that technological world.  See Lotus Development 
Corp., 49 F. 3d, at 820 (Boudin, J., concurring).  In doing so
here, we have not changed the nature of those concepts.  We 
do  not  overturn  or  modify  our  earlier  cases  involving  fair 
use—cases, for example, that involve “knockoff ” products,
journalistic writings, and parodies.  Rather, we here recog-
nize that application of a copyright doctrine such as fair use 
has  long  proved  a  cooperative  effort  of  Legislatures  and 
courts, and that Congress, in our view, intended that it so 
continue.  As such, we have looked to the principles set forth
in  the  fair  use  statute,  §107,  and  set  forth  in  our  earlier 
cases, and applied them to this different kind of copyrighted
work. 

We reach the conclusion that in this case, where Google 
reimplemented  a  user  interface,  taking  only  what  was
needed to allow users to put their accrued talents to work 
in a new and transformative program, Google’s copying of 
the Sun Java API was a fair use of that material as a matter 
of law.  The Federal Circuit’s contrary judgment is reversed,