<s>
Scratch	B-Language
is	O
a	O
high-level	B-Language
block-based	B-Language
visual	B-Language
programming	I-Language
language	I-Language
and	O
website	O
aimed	O
primarily	O
at	O
children	O
as	O
an	O
educational	O
tool	O
,	O
with	O
a	O
target	O
audience	O
of	O
ages	O
8	O
to	O
16	O
.	O
</s>
<s>
Projects	O
can	O
be	O
exported	O
to	O
standalone	B-Application
HTML5	B-Application
,	O
Android	B-Application
apps	B-Application
,	O
Bundle	B-Application
(	O
macOS	B-Application
)	O
and	O
EXE	O
files	O
using	O
external	O
tools	O
.	O
</s>
<s>
Scratch	B-Language
is	O
taught	O
and	O
used	O
in	O
after-school	O
centers	O
,	O
schools	O
,	O
and	O
colleges	O
,	O
as	O
well	O
as	O
other	O
public	O
knowledge	O
institutions	O
.	O
</s>
<s>
Scratch	B-Language
takes	O
its	O
name	O
from	O
a	O
technique	O
used	O
by	O
disk	O
jockeys	O
called	O
"	O
scratching	O
"	O
,	O
where	O
vinyl	O
records	O
are	O
clipped	O
together	O
and	O
manipulated	O
on	O
a	O
turntable	O
to	O
produce	O
different	O
sound	O
effects	O
and	O
music	O
.	O
</s>
<s>
The	O
Scratch	B-Language
interface	O
is	O
divided	O
into	O
three	O
main	O
sections	O
:	O
a	O
stage	O
area	O
,	O
block	O
palette	O
,	O
and	O
a	O
coding	O
area	O
to	O
place	O
and	O
arrange	O
the	O
blocks	O
into	O
scripts	O
that	O
can	O
be	O
run	O
by	O
pressing	O
the	O
green	O
flag	O
or	O
clicking	O
on	O
the	O
code	O
itself	O
.	O
</s>
<s>
The	O
stage	O
area	O
features	O
the	O
results	O
(	O
e.g.	O
,	O
animations	O
,	O
turtle	B-Application
graphics	I-Application
,	O
either	O
in	O
a	O
small	O
or	O
normal	O
size	O
,	O
with	O
a	O
full-screen	O
option	O
also	O
available	O
)	O
and	O
all	O
sprites	O
 '	O
thumbnails	O
being	O
listed	O
in	O
the	O
bottom	O
area	O
.	O
</s>
<s>
+Blocks	O
in	O
Scratch	B-Language
Category	O
Notes	O
Motion	O
Movements	O
of	O
sprites	O
like	O
angles	O
and	O
directions	O
.	O
</s>
<s>
An	O
offline	O
"	O
Desktop	O
Editor	O
"	O
for	O
Scratch	B-Language
3.0	O
is	O
available	O
for	O
Microsoft	B-Application
Windows	I-Application
10	O
and	O
above	O
in	O
the	O
Microsoft	O
Store	O
,	O
Apple	O
's	O
macOS	B-Application
,	O
ChromeOS	O
and	O
Android	B-Application
;	O
this	O
allows	O
the	O
creation	O
and	O
playing	O
of	O
Scratch	B-Language
programs	I-Language
offline	O
.	O
</s>
<s>
The	O
offline	O
editor	O
can	O
also	O
be	O
downloaded	O
in	O
previous	O
versions	O
,	O
such	O
as	O
Scratch	B-Language
2.0	O
and	O
Scratch	B-Language
1.4	O
(	O
an	O
archive	O
of	O
older	O
versions	O
is	O
found	O
)	O
.	O
</s>
<s>
In	O
Scratch	B-Language
,	O
extensions	O
add	O
extra	O
blocks	O
and	O
features	O
that	O
can	O
be	O
used	O
in	O
projects	O
.	O
</s>
<s>
In	O
Scratch	B-Language
2.0	O
and	O
3.0	O
,	O
the	O
extensions	O
were	O
all	O
hardware-based	O
.	O
</s>
<s>
Software-based	O
extensions	O
were	O
added	O
in	O
Scratch	B-Language
3.0	O
,	O
such	O
as	O
text-to-speech	O
voices	O
,	O
along	O
with	O
some	O
new	O
hardware-based	O
extensions	O
like	O
the	O
micro:bit	O
.	O
</s>
<s>
Many	O
of	O
the	O
digital	O
extensions	O
in	O
Scratch	B-Language
3.0	O
used	O
to	O
be	O
regular	O
block	O
categories	O
that	O
were	O
moved	O
to	O
the	O
extensions	O
section	O
to	O
reduce	O
clutter	O
.	O
</s>
<s>
The	O
Scratch	B-Language
Lab	O
has	O
experimental	O
extensions	O
by	O
the	O
Scratch	B-Language
Team	O
,	O
intended	O
to	O
explore	O
whether	O
the	O
blocks	O
may	O
be	O
added	O
to	O
the	O
full	O
website	O
in	O
the	O
future	O
.	O
</s>
<s>
Users	O
can	O
also	O
create	O
their	O
own	O
extensions	O
for	O
Scratch	B-Language
3.0	O
using	O
JavaScript	B-Language
.	O
</s>
<s>
Although	O
the	O
intention	O
for	O
Scratch	B-Language
3.0	O
was	O
to	O
allow	O
unofficial	O
JavaScript	B-Language
extensions	O
,	O
it	O
was	O
abandoned	O
due	O
to	O
moderation	O
risks	O
.	O
</s>
<s>
As	O
a	O
result	O
,	O
several	O
modifications	O
of	O
the	O
Scratch	B-Language
Engine	O
allow	O
JavaScript	B-Language
extensions	O
to	O
be	O
added	O
.	O
</s>
<s>
Scratch	B-Language
3.0	O
is	O
a	O
completely	O
new	O
JavaScript-based	O
codebase	O
made	O
up	O
of	O
multiple	O
components	O
such	O
as	O
"	O
Scratch-GUI	O
,	O
"	O
now	O
based	O
on	O
a	O
library	O
from	O
Blockly	B-Language
,	O
"	O
Scratch-VM	O
,	O
"	O
which	O
interprets	O
code	O
,	O
and	O
"	O
Scratch-Render	O
,	O
"	O
the	O
rendering	O
engine	O
.	O
</s>
<s>
The	O
Scratch	B-Language
Blocks	O
are	O
made	O
using	O
Blockly	B-Language
.	O
</s>
<s>
A	O
paper	O
published	O
in	O
2019	O
by	O
NYU	O
argues	O
and	O
illustrates	O
,	O
for	O
coding	O
music	O
with	O
Scratch	B-Language
,	O
"	O
that	O
the	O
music	O
and	O
sound	O
blocks	O
as	O
currently	O
implemented	O
in	O
Scratch	B-Language
may	O
limit	O
and	O
frustrate	O
meaningful	O
music-making	O
for	O
children	O
,	O
the	O
core	O
user	O
base	O
for	O
Scratch.	O
"	O
</s>
<s>
Scratch	B-Language
is	O
used	O
in	O
many	O
different	O
settings	O
:	O
schools	O
,	O
museums	O
,	O
libraries	O
,	O
community	O
centers	O
,	O
and	O
homes	O
.	O
</s>
<s>
Scratch	B-Language
is	O
designed	O
primarily	O
for	O
users	O
aged	O
8	O
–	O
16	O
,	O
but	O
it	O
is	O
used	O
by	O
all	O
ages	O
and	O
has	O
a	O
sizeable	O
adult	O
user	O
base	O
as	O
of	O
2009	O
.	O
</s>
<s>
In	O
April	O
2020	O
,	O
the	O
Tiobe	O
ranking	O
of	O
the	O
world	O
's	O
programming	O
languages	O
included	O
Scratch	B-Language
into	O
the	O
top	O
20	O
.	O
</s>
<s>
According	O
to	O
Tiobe	O
,	O
there	O
are	O
50	O
million	O
projects	O
written	O
in	O
Scratch	B-Language
,	O
and	O
every	O
month	O
one	O
million	O
new	O
projects	O
are	O
added	O
.	O
</s>
<s>
Scratch	B-Language
is	O
used	O
as	O
the	O
introductory	O
language	O
because	O
the	O
creation	O
of	O
interesting	O
programs	O
is	O
relatively	O
easy	O
,	O
and	O
skills	O
learned	O
can	O
be	O
applied	O
to	O
other	O
programming	O
languages	O
such	O
as	O
Python	B-Language
and	O
Java	B-Language
.	O
</s>
<s>
Scratch	B-Language
is	O
not	O
exclusively	O
for	O
creating	O
games	O
.	O
</s>
<s>
Scratch	B-Language
allows	O
teachers	O
to	O
create	O
conceptual	O
and	O
visual	O
lessons	O
and	O
science	O
lab	O
assignments	O
with	O
animations	O
that	O
help	O
visualize	O
difficult	O
concepts	O
.	O
</s>
<s>
Using	O
Scratch	B-Language
allows	O
young	O
people	O
to	O
understand	O
the	O
logic	O
of	O
programming	O
and	O
how	O
to	O
creatively	O
build	O
and	O
collaborate	O
.	O
</s>
<s>
Scratch	B-Language
is	O
taught	O
to	O
more	O
than	O
800	O
schools	O
and	O
70	O
colleges	O
of	O
DAV	O
organization	O
in	O
India	O
and	O
across	O
the	O
world	O
.	O
</s>
<s>
In	O
higher	O
education	O
,	O
Scratch	B-Language
is	O
used	O
in	O
the	O
first	O
week	O
of	O
Harvard	O
University	O
's	O
CS50	O
introductory	O
computer	O
science	O
course	O
.	O
</s>
<s>
Users	O
of	O
Scratch	B-Language
are	O
called	O
'	O
Scratchers	O
 '	O
.	O
</s>
<s>
Projects	O
can	O
be	O
uploaded	O
directly	O
from	O
the	O
development	O
environment	O
to	O
the	O
Scratch	B-Language
website	O
and	O
any	O
member	O
of	O
the	O
community	O
can	O
download	O
the	O
full	O
source	O
code	O
to	O
study	O
or	O
to	O
remix	O
into	O
new	O
projects	O
.	O
</s>
<s>
Additionally	O
,	O
to	O
encourage	O
the	O
creation	O
and	O
sharing	O
amongst	O
users	O
,	O
the	O
website	O
frequently	O
establishes	O
"	O
Scratch	B-Language
Design	O
Studio	O
"	O
challenges	O
.	O
</s>
<s>
The	O
MIT	O
Scratch	B-Language
Team	O
works	O
to	O
ensure	O
that	O
this	O
community	O
maintains	O
a	O
friendly	O
and	O
respectful	O
environment	O
for	O
all	O
people	O
.	O
</s>
<s>
In	O
this	O
community	O
,	O
Scratch	B-Language
educators	O
share	O
stories	O
,	O
exchange	O
resources	O
,	O
and	O
ask	O
questions	O
.	O
</s>
<s>
The	O
Scratch	B-Language
Wiki	O
is	O
a	O
support	O
resource	O
for	O
Scratch	B-Language
and	O
information	O
about	O
its	O
website	O
,	O
history	O
,	O
and	O
phenomena	O
surrounding	O
it	O
.	O
</s>
<s>
Although	O
supported	O
by	O
the	O
Scratch	B-Language
Team	O
(	O
the	O
developers	O
of	O
Scratch	B-Language
)	O
,	O
it	O
is	O
primarily	O
written	O
by	O
Scratch	B-Language
users	O
(	O
Scratchers	O
)	O
and	O
is	O
hosted	O
independently	O
of	O
the	O
main	O
Scratch	B-Language
website	O
.	O
</s>
<s>
There	O
are	O
also	O
other	O
wikis	O
using	O
languages	O
besides	O
English	O
available	O
on	O
the	O
Scratch	B-Language
Wiki	O
.	O
</s>
<s>
Both	O
Scratch	B-Language
2.0	O
and	O
Scratch	B-Language
3.0	O
'	O
s	O
GUIs	B-Application
are	O
open	O
source	O
on	O
GitHub	B-Application
,	O
and	O
developers	O
may	O
contribute	O
to	O
Scratch	B-Language
.	O
</s>
<s>
The	O
"	O
Scratch	B-Language
Team	O
"	O
role	O
is	O
given	O
out	O
to	O
people	O
who	O
moderate	O
and	O
develop	O
Scratch	B-Language
.	O
</s>
<s>
Scratch	B-Language
Team	O
roles	O
will	O
have	O
an	O
asterisk	O
at	O
the	O
end	O
of	O
their	O
username	O
.	O
</s>
<s>
Various	O
Scratchers	O
have	O
created	O
modifications	O
unaffiliated	O
with	O
Scratch	B-Language
,	O
the	O
most	O
notable	O
ones	O
being	O
and	O
the	O
browser	O
extension	O
.	O
</s>
<s>
Additional	O
popular	O
modifications	O
of	O
Scratch	B-Language
include	O
:	O
</s>
<s>
Scratch	B-Language
Educators	O
can	O
gather	O
in	O
person	O
at	O
Scratch	B-Language
Educator	O
Meetups	O
.	O
</s>
<s>
At	O
these	O
gatherings	O
,	O
Scratch	B-Language
Educators	O
learn	O
from	O
each	O
other	O
and	O
share	O
ideas	O
and	O
strategies	O
that	O
support	O
computational	O
creativity	O
.	O
</s>
<s>
An	O
annual	O
"	O
Scratch	B-Language
Week	O
"	O
,	O
formerly	O
known	O
as	O
"	O
Scratch	B-Language
Day	O
"	O
,	O
is	O
declared	O
in	O
May	O
each	O
year	O
.	O
</s>
<s>
Community	O
members	O
are	O
encouraged	O
to	O
host	O
an	O
event	O
on	O
or	O
around	O
this	O
day	O
,	O
large	O
or	O
small	O
,	O
that	O
celebrates	O
Scratch	B-Language
.	O
</s>
<s>
These	O
events	O
are	O
held	O
worldwide	O
,	O
and	O
a	O
listing	O
can	O
be	O
found	O
on	O
the	O
Scratch	B-Language
Day	O
website	O
.	O
</s>
<s>
Scratch	B-Language
Week	O
is	O
a	O
series	O
focusing	O
on	O
Scratch	B-Language
activities	O
on	O
the	O
Scratch	B-Language
website	O
.	O
</s>
<s>
Every	O
April	O
Fools	O
 '	O
Day	O
,	O
the	O
Scratch	B-Language
Team	O
will	O
play	O
pranks	O
on	O
users	O
and	O
add	O
Easter	O
eggs	O
,	O
one	O
example	O
being	O
turning	O
all	O
the	O
event	O
blocks	O
into	O
cat	O
versions	O
of	O
the	O
same	O
blocks	O
.	O
</s>
<s>
These	O
blocks	O
were	O
called	O
"	O
cat	O
blocks	O
"	O
and	O
can	O
be	O
downloaded	O
as	O
one	O
of	O
the	O
many	O
downloadable	O
Scratch	B-Language
add-ons	O
.	O
</s>
<s>
In	O
the	O
early	O
2000s	O
,	O
the	O
MIT	O
Media	O
Lab	O
's	O
Lifelong	O
Kindergarten	O
group	O
(	O
LLK	O
)	O
was	O
developing	O
visual	B-Language
programming	I-Language
languages	I-Language
targeted	O
towards	O
children	O
.	O
</s>
<s>
The	O
LLK	O
,	O
led	O
by	O
Mitchel	O
Resnick	O
,	O
in	O
partnership	O
with	O
Yasmin	O
Kafai	O
's	O
team	O
at	O
UCLA	O
worked	O
closely	O
with	O
Computer	O
Clubhouses	O
in	O
Boston	O
and	O
Los	O
Angeles	O
to	O
develop	O
Scratch	B-Language
,	O
grounding	O
its	O
design	O
in	O
the	O
practices	O
and	O
social	O
dynamics	O
of	O
these	O
after-school	O
youth	O
centers	O
.	O
</s>
<s>
Similar	O
to	O
AgentSheets	B-Language
Scratch	B-Language
employed	O
concepts	O
of	O
Tactile	O
Programming	O
later	O
known	O
as	O
blocks-based	O
programming	O
.	O
</s>
<s>
Scratch	B-Language
was	O
made	O
with	O
the	O
intention	O
to	O
teach	O
kids	O
to	O
program	O
.	O
</s>
<s>
The	O
philosophy	O
of	O
Scratch	B-Language
encourages	O
the	O
sharing	O
,	O
reuse	O
,	O
and	O
combination	O
of	O
code	O
,	O
as	O
indicated	O
by	O
the	O
team	O
slogan	O
,	O
"	O
Imagine	O
,	O
Program	O
,	O
Share	O
"	O
.	O
</s>
<s>
Projects	O
created	O
and	O
remixed	O
with	O
Scratch	B-Language
are	O
licensed	O
under	O
the	O
Creative	O
Commons	O
Attribution-Share	O
Alike	O
License	O
.	O
</s>
<s>
Scratch	B-Language
automatically	O
gives	O
credit	O
to	O
the	O
user	O
who	O
created	O
the	O
original	O
project	O
and	O
program	O
in	O
the	O
top	O
part	O
of	O
the	O
project	O
page	O
.	O
</s>
<s>
Scratch	B-Language
was	O
developed	O
based	O
on	O
ongoing	O
interaction	O
with	O
youth	O
and	O
staff	O
at	O
Computer	O
Clubhouses	O
.	O
</s>
<s>
The	O
use	O
of	O
Scratch	B-Language
at	O
Computer	O
Clubhouses	O
served	O
as	O
a	O
model	O
for	O
other	O
after-school	O
centers	O
demonstrating	O
how	O
informal	O
learning	O
settings	O
can	O
support	O
the	O
development	O
of	O
technological	O
fluency	O
.	O
</s>
<s>
Scratch	B-Language
2.0	O
was	O
released	O
on	O
9	O
May	O
2013	O
.	O
</s>
<s>
The	O
Scratch	B-Language
2.0	O
Offline	O
editor	O
could	O
be	O
downloaded	O
for	O
Windows	O
,	O
Mac	O
and	O
Linux	B-Application
directly	O
from	O
Scratch	B-Language
's	O
website	O
,	O
although	O
support	O
for	O
Linux	B-Application
was	O
later	O
dropped	O
.	O
</s>
<s>
The	O
unofficial	O
mobile	O
version	O
had	O
to	O
be	O
downloaded	O
from	O
the	O
Scratch	B-Language
forums	O
.	O
</s>
<s>
Scratch	B-Language
3.0	O
was	O
first	O
announced	O
by	O
the	O
Scratch	B-Language
Team	O
in	O
2016	O
.	O
</s>
<s>
A	O
beta	O
version	O
of	O
Scratch	B-Language
3.0	O
was	O
released	O
on	O
1	O
August	O
2018	O
.	O
for	O
use	O
on	O
most	O
browsers	O
;	O
with	O
the	O
notable	O
exception	O
of	O
Internet	B-Application
Explorer	I-Application
.	O
</s>
<s>
Scratch	B-Language
3.0	O
,	O
the	O
first	O
3.x	O
release	O
version	O
,	O
was	O
released	O
on	O
2	O
January	O
2019	O
.	O
</s>
<s>
In	O
Scratch	B-Language
1.4	O
,	O
an	O
*	O
file	O
was	O
the	O
file	O
format	O
used	O
to	O
store	O
projects	O
.	O
</s>
<s>
It	O
contains	O
:	O
"	O
thumbnail	O
"	O
,	O
a	O
thumbnail	O
of	O
the	O
project	O
's	O
stage	O
;	O
"	O
author	O
"	O
,	O
the	O
username	O
of	O
the	O
project	O
's	O
creator	O
;	O
"	O
comment	O
"	O
,	O
the	O
Project	O
Notes	O
;	O
"	O
history	O
"	O
,	O
the	O
save	O
and	O
upload	O
log	O
;	O
"	O
scratch-version	O
"	O
,	O
the	O
version	O
of	O
Scratch	B-Language
used	O
to	O
save	O
the	O
file	O
;	O
</s>
<s>
Scratch	B-Language
2.0	O
uses	O
the	O
*	O
file	O
format	O
.	O
</s>
<s>
These	O
are	O
zip	O
files	O
containing	O
a	O
.json	B-General_Concept
file	O
as	O
well	O
as	O
the	O
contents	O
of	O
the	O
Scratch	B-Language
project	O
including	O
sounds	O
(	O
stored	O
as	O
)	O
and	O
images	O
(	O
stored	O
as	O
)	O
.	O
</s>
<s>
The	O
ScratchX	O
experimental	O
version	O
of	O
Scratch	B-Language
used	O
the	O
file	O
format	O
.	O
</s>
<s>
Scratch	B-Language
3.0	O
uses	O
the	O
*	O
format	O
,	O
which	O
is	O
very	O
similar	O
to	O
*	O
,	O
one	O
difference	O
being	O
the	O
sound	O
.	O
</s>
<s>
Although	O
the	O
main	O
Scratch	B-Language
website	O
now	O
runs	O
only	O
the	O
current	O
version	O
(	O
Scratch	B-Language
3.0	O
)	O
,	O
the	O
offline	O
editors	O
for	O
Scratch	B-Language
2.0	O
(	O
and	O
the	O
earlier	O
Scratch	B-Language
1.4	O
)	O
are	O
still	O
available	O
for	O
download	O
and	O
can	O
be	O
used	O
to	O
create	O
and	O
run	O
games	O
locally	O
.	O
</s>
<s>
It	O
is	O
still	O
possible	O
to	O
upload	O
projects	O
from	O
the	O
Scratch	B-Language
2.0	O
launcher	O
,	O
which	O
are	O
immediately	O
converted	O
into	O
Scratch	B-Language
3.0	O
when	O
uploaded	O
to	O
the	O
main	O
site	O
.	O
</s>
<s>
There	O
is	O
also	O
an	O
offline	O
version	O
of	O
Scratch	B-Language
3.0	O
.	O
</s>
<s>
The	O
editor	O
of	O
Scratch	B-Language
1.4	O
and	O
below	O
was	O
written	O
in	O
Squeak	B-Operating_System
,	O
while	O
its	O
online	O
project	O
viewer	O
was	O
written	O
in	O
Java	B-Language
,	O
and	O
a	O
player	O
written	O
in	O
Adobe	B-Operating_System
Flash	I-Operating_System
was	O
later	O
added	O
.	O
</s>
<s>
Scratch	B-Language
2.0	O
relied	O
on	O
Adobe	B-Operating_System
Flash	I-Operating_System
for	O
the	O
online	O
version	O
,	O
and	O
Adobe	B-Operating_System
AIR	I-Operating_System
for	O
the	O
offline	O
editor	O
.	O
</s>
<s>
In	O
Scratch	B-Language
2.0	O
,	O
the	O
stage	O
area	O
is	O
on	O
the	O
left	O
side	O
,	O
with	O
the	O
programming	O
blocks	O
palette	O
in	O
the	O
middle	O
the	O
coding	O
area	O
on	O
the	O
right	O
.	O
</s>
<s>
The	O
blocks	O
palette	O
in	O
Scratch	B-Language
2.0	O
is	O
made	O
of	O
discrete	O
sections	O
that	O
are	O
not	O
scrollable	O
from	O
one	O
to	O
the	O
next	O
;	O
the	O
table	O
below	O
shows	O
the	O
different	O
sections	O
:	O
</s>
<s>
Scratch	B-Language
2.0	O
changed	O
how	O
sounds	O
were	O
imported	O
,	O
so	O
many	O
Scratch	B-Language
1.4	O
sounds	O
stopped	O
working	O
.	O
</s>
<s>
In	O
Scratch	B-Language
2.0	O
,	O
extensions	O
were	O
all	O
hardware-based	O
.	O
</s>
<s>
Scratch	B-Language
uses	O
event-driven	B-Application
programming	I-Application
with	O
multiple	O
active	O
objects	O
called	O
sprites	O
.	O
</s>
<s>
Sprites	O
can	O
be	O
drawn	O
,	O
as	O
vector	O
or	O
bitmap	O
graphics	O
,	O
from	O
scratch	B-Language
in	O
a	O
simple	O
editor	O
that	O
is	O
part	O
of	O
Scratch	B-Language
,	O
or	O
can	O
be	O
imported	O
from	O
external	O
sources	O
.	O
</s>
<s>
Scratch	B-Language
3.0	O
only	O
supports	O
one-dimensional	O
arrays	B-Data_Structure
,	O
known	O
as	O
"	O
lists	O
"	O
,	O
and	O
floating-point	O
scalars	O
and	O
strings	O
are	O
supported	O
,	O
but	O
with	O
limited	O
string	O
manipulation	O
ability	O
.	O
</s>
<s>
There	O
is	O
a	O
strong	O
contrast	O
between	O
the	O
powerful	O
multimedia	O
functions	O
and	O
multi-threaded	O
programming	O
style	O
and	O
the	O
rather	O
limited	O
scope	O
of	O
the	O
Scratch	B-Language
programming	I-Language
language	I-Language
.	O
</s>
<s>
Scratch	B-Language
2.0	O
does	O
not	O
treat	O
procedures	O
as	O
first	B-Application
class	I-Application
structures	O
and	O
has	O
limited	O
file	B-General_Concept
I/O	I-General_Concept
options	O
with	O
Scratch	B-Language
2.0	O
Extension	O
Protocol	O
,	O
an	O
experimental	O
extension	O
feature	O
that	O
allows	O
interaction	O
between	O
Scratch	B-Language
2.0	O
and	O
other	O
programs	O
.	O
</s>
<s>
The	O
Extension	O
protocol	O
allows	O
interfacing	O
with	O
hardware	O
boards	O
such	O
as	O
Lego	B-Application
Mindstorms	I-Application
or	O
Arduino	O
.	O
</s>
<s>
Scratch	B-Language
2.0	O
was	O
implemented	O
in	O
ActionScript	B-Operating_System
,	O
with	O
an	O
experimental	O
JavaScript-based	O
interpreter	O
being	O
developed	O
in	O
parallel	O
.	O
</s>
<s>
Scratch	B-Language
1.4	O
was	O
based	O
on	O
Squeak	B-Operating_System
,	O
which	O
is	O
based	O
on	O
Smalltalk-80	B-Application
.	O
</s>
<s>
A	O
number	O
of	O
Scratch	B-Language
derivatives	O
called	O
Scratch	B-Language
Modifications	O
have	O
been	O
created	O
using	O
the	O
source	O
code	O
of	O
Scratch	B-Language
1.4	O
.	O
</s>
<s>
These	O
programs	O
are	O
a	O
variant	O
of	O
Scratch	B-Language
that	O
normally	O
include	O
a	O
few	O
extra	O
blocks	O
or	O
changes	O
to	O
the	O
GUI	B-Application
.	O
</s>
<s>
TurboWarp	O
is	O
an	O
unofficial	O
modification	O
of	O
Scratch	B-Language
3.0	O
that	O
improves	O
the	O
performance	O
of	O
Scratch	B-Language
by	O
compiling	O
projects	O
to	O
JavaScript	B-Language
and	O
allows	O
the	O
loading	O
of	O
external	O
extensions	O
.	O
</s>
<s>
A	O
more	O
advanced	O
visual	B-Language
programming	I-Language
language	I-Language
inspired	O
by	O
Scratch	B-Language
is	O
Snap	O
!,	O
featuring	O
first	B-Application
class	I-Application
procedures	I-Application
(	O
their	O
mathematical	O
foundations	O
are	O
called	O
also	O
lambda	B-Language
calculus	I-Language
)	O
,	O
first-class	O
lists	O
(	O
including	O
lists	O
of	O
lists	O
)	O
,	O
and	O
first-class	O
truly	O
object-oriented	O
sprites	O
with	O
prototyping	O
inheritance	O
,	O
and	O
nestable	O
sprites	O
,	O
which	O
are	O
not	O
part	O
of	O
Scratch	B-Language
.	O
</s>
<s>
Snap	B-Application
!	I-Application
</s>
<s>
(	O
previously	O
"	O
BYOB	B-Application
"	O
)	O
was	O
developed	O
by	O
Jens	O
Mönig	O
with	O
documentation	O
provided	O
by	O
Brian	O
Harvey	O
from	O
University	O
of	O
California	O
,	O
Berkeley	O
and	O
has	O
been	O
used	O
to	O
teach	O
"	O
The	O
Beauty	O
and	O
Joy	O
of	O
Computing	O
"	O
introductory	O
course	O
in	O
CS	O
for	O
non-CS-major	O
students	O
.	O
</s>
<s>
Both	O
of	O
them	O
were	O
members	O
of	O
the	O
Scratch	B-Language
Team	O
before	O
designing	O
"	O
Snap	B-Application
!	I-Application
</s>
<s>
In	O
July	O
2014	O
,	O
ScratchJr	B-Application
was	O
released	O
for	O
iPad	B-Device
,	O
and	O
in	O
2016	O
,	O
ScratchJr	B-Application
for	O
Android	B-Application
.	O
</s>
<s>
Although	O
heavily	O
inspired	O
by	O
Scratch	B-Language
and	O
co-led	O
by	O
Mitch	O
Resnick	O
,	O
it	O
is	O
nonetheless	O
a	O
complete	O
rewrite	O
designed	O
for	O
younger	O
children	O
—	O
targeting	O
ages	O
5	O
through	O
7	O
.	O
</s>
<s>
In	O
August	O
2020	O
,	O
GreatFire	O
announced	O
that	O
the	O
Chinese	O
government	O
had	O
blocked	O
access	O
to	O
the	O
Scratch	B-Language
website	O
.	O
</s>
