<s>
ProGuard	B-Language
is	O
an	O
open	B-Application
source	I-Application
command-line	B-Application
tool	I-Application
that	O
shrinks	O
,	O
optimizes	O
and	O
obfuscates	O
Java	B-Language
code	I-Language
.	O
</s>
<s>
It	O
is	O
able	O
to	O
optimize	O
bytecode	O
as	O
well	O
as	O
detect	O
and	O
remove	O
unused	O
instructions	B-General_Concept
.	O
</s>
<s>
ProGuard	B-Language
is	O
free	O
software	O
and	O
is	O
distributed	O
under	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
,	O
version	O
2	O
.	O
</s>
<s>
ProGuard	B-Language
was	O
distributed	O
as	O
part	O
of	O
the	O
Android	O
SDK	O
and	O
ran	O
when	O
building	B-Language
the	O
application	O
in	O
release	O
mode	O
.	O
</s>
<s>
Works	O
with	O
Java	B-Language
Micro	I-Language
Edition	I-Language
and	O
Android	O
;	O
</s>
<s>
ProGuard	B-Language
obfuscates	O
Java	B-Language
and	O
Android	O
programs	O
by	O
renaming	O
classes	O
,	O
fields	B-Application
,	O
and	O
methods	B-Language
using	O
meaningless	O
names	O
,	O
making	O
it	O
harder	O
to	O
reverse-engineer	O
the	O
final	O
application	O
.	O
</s>
<s>
Besides	O
removing	O
unused	O
instructions	B-General_Concept
from	O
the	O
compiled	B-Language
bytecode	O
,	O
ProGuard	B-Language
optimizes	O
it	O
using	O
techniques	O
such	O
as	O
control	O
flow	O
analysis	O
,	O
data-flow	O
analysis	O
,	O
partial	O
evaluation	O
,	O
static	O
single	O
assignment	O
,	O
global	O
value	O
numbering	O
,	O
and	O
liveness	O
analysis	O
.	O
</s>
<s>
ProGuard	B-Language
can	O
remove	O
many	O
types	O
of	O
unused	O
and	O
duplicated	O
code	O
,	O
perform	O
over	O
200	O
peephole	O
optimizations	O
,	O
reduce	O
variable	O
allocation	O
,	O
inline	O
constant	O
and	O
short	O
methods	B-Language
,	O
simplify	O
tail	B-Language
recursion	I-Language
calls	O
,	O
remove	O
logging	O
code	O
,	O
among	O
others	O
.	O
</s>
