<s>
Parrot	B-Language
was	O
a	O
register-based	B-Application
process	O
virtual	B-Architecture
machine	I-Architecture
designed	O
to	O
run	O
dynamic	B-Language
languages	I-Language
efficiently	O
.	O
</s>
<s>
It	O
is	O
possible	O
to	O
compile	B-Language
Parrot	B-Language
assembly	I-Language
language	I-Language
and	O
Parrot	B-Language
intermediate	I-Language
representation	I-Language
(	O
PIR	O
,	O
an	O
intermediate	O
language	O
)	O
to	O
Parrot	B-Language
bytecode	O
and	O
execute	O
it	O
.	O
</s>
<s>
Parrot	B-Language
is	O
free	B-Application
and	I-Application
open	I-Application
source	I-Application
software	I-Application
.	O
</s>
<s>
Parrot	B-Language
was	O
started	O
by	O
the	O
Perl	B-Language
community	O
and	O
is	O
developed	O
with	O
help	O
from	O
the	O
open	B-Application
source	I-Application
and	O
free	B-Application
software	I-Application
communities	O
.	O
</s>
<s>
As	O
a	O
result	O
,	O
it	O
is	O
focused	O
on	O
license	O
compatibility	O
with	O
Perl	B-Language
(	O
Artistic	B-License
License	I-License
2.0	I-License
)	O
,	O
platform	O
compatibility	O
across	O
a	O
broad	O
array	O
of	O
systems	O
,	O
processor	O
architecture	O
compatibility	O
across	O
most	O
modern	O
processors	O
,	O
speed	O
of	O
execution	O
,	O
small	O
size	O
(	O
around	O
700k	O
depending	O
on	O
platform	O
)	O
,	O
and	O
the	O
flexibility	O
to	O
handle	O
the	O
varying	O
demands	O
made	O
by	O
Raku	B-Application
and	O
other	O
modern	O
dynamic	B-Language
languages	I-Language
.	O
</s>
<s>
Version	O
1.0	O
,	O
with	O
a	O
stable	O
application	B-Application
programming	I-Application
interface	I-Application
(	O
API	B-Application
)	O
for	O
development	O
,	O
was	O
released	O
on	O
March	O
17	O
,	O
2009	O
.	O
</s>
<s>
Parrot	B-Language
was	O
officially	O
discontinued	O
in	O
August	O
2021	O
,	O
after	O
being	O
supplanted	O
by	O
MoarVM	B-Language
in	O
its	O
main	O
use	O
(	O
Raku	B-Application
)	O
and	O
never	O
becoming	O
a	O
mainstream	O
VM	O
for	O
any	O
of	O
its	O
other	O
supported	O
languages	O
.	O
</s>
<s>
The	O
name	O
Parrot	B-Language
came	O
from	O
an	O
April	O
Fool	O
's	O
joke	O
which	O
announced	O
a	O
hypothetical	O
language	O
,	O
named	O
Parrot	B-Language
,	O
that	O
would	O
unify	O
Python	B-Language
and	O
Perl	B-Language
.	O
</s>
<s>
The	O
name	O
was	O
later	O
adopted	O
by	O
this	O
project	O
(	O
initially	O
a	O
part	O
of	O
the	O
Raku	B-Application
development	O
effort	O
)	O
which	O
aims	O
to	O
support	O
Raku	B-Application
,	O
Python	B-Language
,	O
and	O
other	O
programming	O
languages	O
.	O
</s>
<s>
Several	O
languages	O
are	O
being	O
ported	O
to	O
run	O
on	O
the	O
Parrot	B-Language
virtual	I-Language
machine	I-Language
.	O
</s>
<s>
The	O
Parrot	B-Language
Foundation	O
was	O
dissolved	O
in	O
2014	O
.	O
</s>
<s>
The	O
Foundation	O
was	O
created	O
in	O
2008	O
to	O
hold	O
the	O
copyright	O
and	O
trademarks	O
of	O
the	O
Parrot	B-Language
project	O
,	O
to	O
help	O
drive	O
development	O
of	O
language	B-Application
implementations	I-Application
and	O
the	O
core	O
codebase	O
,	O
to	O
provide	O
a	O
base	O
for	O
growing	O
the	O
Parrot	B-Language
community	O
,	O
and	O
to	O
reach	O
out	O
to	O
other	O
language	O
communities	O
.	O
</s>
<s>
The	O
goal	O
of	O
the	O
Parrot	B-Language
virtual	I-Language
machine	I-Language
is	O
to	O
host	O
client	O
languages	O
and	O
allow	O
inter-operation	O
between	O
them	O
.	O
</s>
<s>
Several	O
hurdles	O
exist	O
in	O
accomplishing	O
this	O
goal	O
,	O
in	O
particular	O
the	O
difficulty	O
of	O
mapping	O
high-level	O
concepts	O
,	O
data	O
,	O
and	O
data	B-General_Concept
structures	I-General_Concept
between	O
languages	O
.	O
</s>
<s>
The	O
differing	O
properties	O
of	O
statically	O
and	O
dynamically	O
typed	O
languages	O
have	O
motivated	O
the	O
design	O
of	O
Parrot	B-Language
.	O
</s>
<s>
Current	O
popular	O
virtual	B-Architecture
machines	I-Architecture
such	O
as	O
the	O
Java	B-Language
virtual	I-Language
machine	I-Language
and	O
the	O
Common	O
Language	O
Runtime	O
,	O
for	O
the	O
.NET	O
platform	O
,	O
have	O
been	O
designed	O
for	O
statically	O
typed	O
languages	O
,	O
while	O
the	O
languages	O
targeted	O
by	O
Parrot	B-Language
are	O
dynamically	O
typed	O
.	O
</s>
<s>
Virtual	B-Architecture
machines	I-Architecture
such	O
as	O
the	O
Java	B-Language
virtual	I-Language
machine	I-Language
and	O
the	O
current	O
Perl	B-Language
5	O
virtual	B-Architecture
machine	I-Architecture
are	O
also	O
stack	B-Application
based	I-Application
.	O
</s>
<s>
Parrot	B-Language
developers	O
see	O
Parrot	B-Language
's	O
inclusion	O
of	O
registers	O
as	O
an	O
advantage	O
,	O
as	O
it	O
therefore	O
more	O
closely	O
resembles	O
a	O
hardware	O
design	O
,	O
allowing	O
the	O
vast	O
literature	O
on	O
compiler	B-Application
optimization	I-Application
to	O
be	O
used	O
in	O
generating	O
bytecode	O
for	O
the	O
Parrot	B-Language
virtual	I-Language
machine	I-Language
that	O
could	O
run	O
at	O
speeds	O
closer	O
to	O
machine	B-Language
code	I-Language
.	O
</s>
<s>
Other	O
register-based	B-Application
virtual	B-Architecture
machines	I-Architecture
have	O
inspired	O
parts	O
of	O
Parrot	B-Language
's	O
design	O
,	O
including	O
LLVM	B-Application
,	O
the	O
Lua	B-Language
VM	O
and	O
Inferno	O
's	O
Dis	O
.	O
</s>
<s>
Parrot	B-Language
has	O
rich	O
support	O
for	O
several	O
features	O
of	O
functional	B-Language
programming	I-Language
including	O
closures	B-Language
and	O
continuations	O
,	O
both	O
of	O
which	O
can	O
be	O
particularly	O
difficult	O
to	O
implement	O
correctly	O
and	O
portably	O
,	O
especially	O
in	O
conjunction	O
with	O
exception	B-General_Concept
handling	I-General_Concept
and	O
threading	B-Operating_System
.	O
</s>
<s>
The	O
biggest	O
advantage	O
is	O
the	O
dynamic	O
extendability	O
of	O
objects	O
with	O
methods	O
,	O
which	O
allows	O
for	O
polymorphic	O
containers	O
(	O
PMCs	O
)	O
and	O
associated	O
opcodes	B-Language
.	O
</s>
<s>
Implementing	O
solutions	O
to	O
these	O
problems	O
at	O
the	O
virtual	B-Architecture
machine	I-Architecture
level	O
obviates	O
the	O
need	O
to	O
solve	O
these	O
problems	O
in	O
the	O
individual	O
client	O
languages	O
.	O
</s>
<s>
Parrot	B-Language
provides	O
a	O
suite	O
of	O
compiler-writing	O
tools	O
which	O
includes	O
the	O
Parser	B-Language
Grammar	I-Language
Engine	I-Language
(	O
PGE	B-Language
)	O
,	O
a	O
hybrid	O
parser-generator	O
that	O
can	O
express	O
a	O
recursive	B-Application
descent	I-Application
parser	I-Application
as	O
well	O
as	O
an	O
operator-precedence	B-Application
parser	I-Application
,	O
allowing	O
free	B-Application
transition	O
between	O
the	O
two	O
in	O
a	O
single	O
grammar	O
.	O
</s>
<s>
The	O
PGE	B-Language
feeds	O
into	O
the	O
Tree	O
Grammar	O
Engine	O
(	O
TGE	O
)	O
which	O
further	O
transforms	O
the	O
parse-tree	O
generated	O
by	O
PGE	B-Language
for	O
optimization	O
and	O
ultimately	O
for	O
code	O
generation	O
.	O
</s>
<s>
Many	O
languages	O
already	O
have	O
compiler	B-Language
front-ends	O
designed	O
for	O
Parrot	B-Language
;	O
however	O
,	O
many	O
of	O
them	O
are	O
still	O
only	O
partially	O
functional	O
.	O
</s>
<s>
There	O
are	O
three	O
forms	O
of	O
program	O
code	O
for	O
Parrot	B-Language
:	O
</s>
<s>
Bytecode	O
is	O
binary	O
and	O
is	O
natively	O
interpreted	O
by	O
Parrot	B-Language
.	O
</s>
<s>
Bytecode	O
is	O
usually	O
stored	O
in	O
files	O
with	O
the	O
filename	O
extension	O
"	O
.pbc	B-Language
"	O
.	O
</s>
<s>
Parrot	B-Language
assembly	I-Language
language	I-Language
(	O
PASM	O
)	O
is	O
the	O
low	O
level	O
language	O
that	O
compiles	B-Language
down	O
to	O
bytecode	O
.	O
</s>
<s>
PASM	O
code	O
is	O
usually	O
stored	O
in	O
files	O
with	O
the	O
filename	O
extension	O
"	O
.pasm	B-Language
"	O
.	O
</s>
<s>
Parrot	B-Language
intermediate	I-Language
representation	I-Language
(	O
PIR	O
)	O
is	O
a	O
slightly	O
higher	O
level	O
language	O
than	O
PASM	O
and	O
also	O
compiles	B-Language
down	O
to	O
bytecode	O
.	O
</s>
<s>
It	O
is	O
the	O
primary	O
target	O
of	O
language	B-Application
implementations	I-Application
.	O
</s>
<s>
PIR	O
transparently	O
manages	O
Parrot	B-Language
's	O
inter-routine	O
calling	O
conventions	O
,	O
provides	O
improved	O
syntax	O
,	O
register	O
allocation	O
,	O
and	O
more	O
.	O
</s>
<s>
PIR	O
code	O
is	O
usually	O
stored	O
in	O
files	O
with	O
the	O
filename	O
extension	O
"	O
.pir	B-Language
"	O
.	O
</s>
<s>
Parrot	B-Language
is	O
register-based	B-Application
like	O
most	O
hardware	O
CPUs	B-General_Concept
,	O
and	O
unlike	O
most	O
virtual	B-Architecture
machines	I-Architecture
,	O
which	O
are	O
stack-based	O
.	O
</s>
<s>
Parrot	B-Language
provides	O
four	O
types	O
of	O
registers	O
:	O
</s>
<s>
Parrot	B-Language
provides	O
an	O
arbitrary	O
number	O
of	O
registers	O
;	O
this	O
number	O
is	O
fixed	O
at	O
compile	B-Language
time	O
per	O
subroutine	O
.	O
</s>
<s>
Until	O
late	O
2005	O
,	O
Dan	O
Sugalski	O
was	O
the	O
lead	O
designer	O
and	O
chief	O
architect	O
of	O
Parrot	B-Language
.	O
</s>
<s>
Chip	O
Salzenberg	O
,	O
a	O
longtime	O
Perl	B-Language
,	O
Linux	O
kernel	O
,	O
and	O
C++	O
hacker	O
,	O
took	O
over	O
until	O
mid-2006	O
,	O
when	O
he	O
became	O
the	O
lead	O
developer	O
.	O
</s>
<s>
Allison	O
Randal	O
,	O
the	O
lead	O
developer	O
of	O
Punie	B-Language
and	O
chief	O
architect	O
of	O
Parrot	B-Language
's	O
compiler	B-Language
tools	O
,	O
was	O
the	O
chief	O
architect	O
until	O
mid-October	O
2010	O
when	O
she	O
stepped	O
down	O
and	O
chose	O
Christoph	O
Otto	O
as	O
the	O
new	O
chief	O
architect	O
.	O
</s>
<s>
Development	O
discussions	O
take	O
place	O
primarily	O
on	O
the	O
#parrot	O
channel	O
on	O
irc.perl.org	O
.	O
</s>
<s>
In	O
addition	O
,	O
there	O
are	O
weekly	O
moderated	O
meetings	O
for	O
Parrot	B-Language
and	O
language	O
developers	O
hosted	O
in	O
#parrotsketch	O
on	O
the	O
same	O
network	O
.	O
</s>
<s>
Much	O
discussion	O
also	O
occurs	O
on	O
the	O
parrot-dev	O
mailing	O
list	O
,	O
hosted	O
by	O
parrot.org	O
.	O
</s>
<s>
Design	O
discussions	O
exist	O
in	O
the	O
form	O
of	O
Parrot	B-Language
Design	O
Documents	O
,	O
or	O
PDDs	O
,	O
in	O
the	O
Parrot	B-Language
repository	O
.	O
</s>
<s>
Parrot	B-Language
hackers	O
turn	O
these	O
documents	O
into	O
executable	O
tests	O
,	O
and	O
then	O
existing	O
features	O
.	O
</s>
<s>
The	O
Parrot	B-Language
team	O
releases	O
a	O
new	O
stable	O
version	O
of	O
the	O
software	O
on	O
the	O
third	O
Tuesday	O
of	O
every	O
month	O
.	O
</s>
