<s>
Snap	B-Application
!	I-Application
</s>
<s>
(	O
formerly	O
Build	B-Application
Your	I-Application
Own	I-Application
Blocks	I-Application
)	O
is	O
a	O
free	O
,	O
block-based	O
educational	B-Language
graphical	O
programming	O
language	O
and	O
online	O
community	O
allowing	O
students	O
to	O
explore	O
,	O
create	O
,	O
and	O
remix	O
interactive	O
animations	O
,	O
games	O
,	O
stories	O
,	O
and	O
more	O
,	O
while	O
learning	O
about	O
mathematical	O
and	O
computational	O
ideas	O
.	O
</s>
<s>
While	O
inspired	O
by	O
Scratch	B-Language
,	O
Snap	B-Application
!	I-Application
</s>
<s>
The	O
Snap	B-Application
!	I-Application
</s>
<s>
editor	O
,	O
and	O
programs	O
created	O
in	O
it	O
,	O
are	O
web	B-Application
applications	I-Application
that	O
run	O
in	O
the	O
browser	O
(	O
like	O
Scratch	B-Language
3	I-Language
)	O
without	O
requiring	O
installation	B-Application
.	O
</s>
<s>
Default	O
interface.jpg	O
|thumb|left|420px|Three	O
resizable	O
columns	O
,	O
containing	O
five	O
regions	O
,	O
in	O
Snap	B-Application
!	I-Application
</s>
<s>
Snap	B-Application
!	I-Application
</s>
<s>
The	O
most	O
important	O
features	O
that	O
Snap	B-Application
!	I-Application
</s>
<s>
offers	O
,	O
but	O
Scratch	B-Language
does	O
not	O
,	O
include	O
:	O
</s>
<s>
expressions	O
using	O
anonymous	B-General_Concept
functions	I-General_Concept
,	O
represented	O
by	O
a	O
block	O
inside	O
a	O
gray	O
ring	O
,	O
having	O
one	O
or	O
more	O
empty	O
slot(s )	O
/argument	O
( s	O
)	O
that	O
are	O
filled	O
by	O
a	O
"	O
higher	O
order	O
function	O
"	O
(	O
the	O
one	O
that	O
is	O
calling	O
the	O
anonymous	O
one	O
)	O
.	O
</s>
<s>
(	O
Their	O
computer-science	B-General_Concept
theoretical	O
basis	O
is	O
First	B-Application
class	I-Application
functions	I-Application
,	O
which	O
in	O
turn	O
have	O
Lambda	B-Language
calculus	I-Language
as	O
their	O
even	O
more	O
abstract	O
,	O
mathematical	O
,	O
foundation	O
)	O
,	O
</s>
<s>
First	O
class	O
sprites	O
(	O
in	O
other	O
words	O
prototype-oriented	B-Application
instance-based	I-Application
classless	I-Application
object	I-Application
programming	I-Application
)	O
,	O
</s>
<s>
codification	O
of	O
Snap	B-Application
!	I-Application
</s>
<s>
programs	O
to	O
text	O
languages	O
such	O
as	O
Python	B-Language
,	O
JavaScript	B-Language
,	O
C	B-Language
,	O
etc	O
.	O
</s>
<s>
metaprogramming	B-Application
,	O
reflection	O
,	O
and	O
macros	O
.	O
</s>
<s>
Alonzo	O
,	O
the	O
mascot	O
of	O
Snap	O
!,	O
bears	O
the	O
name	O
of	O
Alonzo	O
Church	O
,	O
the	O
inventor	O
of	O
a	O
model	O
of	O
computation	O
in	O
which	O
a	O
universal	O
function	O
,	O
represented	O
by	O
lambda	B-General_Concept
,	O
can	O
create	O
any	O
function	O
behavior	O
by	O
calling	O
it	O
on	O
itself	O
in	O
various	O
combinations	O
.	O
</s>
<s>
The	O
mascot	O
is	O
a	O
modified	O
version	O
of	O
Gobo	O
from	O
Scratch	B-Language
.	O
</s>
<s>
Because	O
Alonzo	O
Church	O
's	O
work	O
is	O
called	O
lambda	B-Language
calculus	I-Language
,	O
the	O
mascot	O
's	O
hair	O
is	O
shaped	O
as	O
the	O
Greek	O
letter	O
lambda	B-General_Concept
.	O
</s>
<s>
Extended	O
sets	O
of	O
blocks	O
can	O
be	O
found	O
in	O
Snap	B-Application
!	I-Application
</s>
<s>
libraries	O
,	O
such	O
as	O
the	O
'	B-Architecture
streams	I-Architecture
 '	I-Architecture
library	O
that	O
enables	O
one	O
to	O
make	O
the	O
complete	O
,	O
infinite	O
Fibonacci	O
sequence	O
,	O
for	O
example	O
,	O
using	O
the	O
special	O
blocks	O
( 	O
 '	O
stream	O
 '	O
,	O
'	O
show	O
stream	O
 '	O
,	O
'	O
tail	O
of	O
stream	O
 '	O
,	O
and	O
'	O
map	O
(	O
)	O
over	O
stream	O
 '	O
block	O
)	O
from	O
the	O
library	O
.	O
</s>
<s>
The	O
web-based	B-Application
Snap	B-Application
!	I-Application
</s>
<s>
and	O
older	O
desktop-based	O
BYOB	B-Application
have	O
been	O
both	O
developed	O
by	O
Jens	O
Mönig	O
for	O
Windows	B-Application
,	O
OS	B-Operating_System
X	I-Operating_System
and	O
Linux	B-Application
with	O
design	O
ideas	O
and	O
documentation	O
provided	O
by	O
Brian	O
Harvey	O
from	O
University	O
of	O
California	O
,	O
Berkeley	O
and	O
have	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
computer	B-General_Concept
science	I-General_Concept
(	O
CS	B-Language
)	O
for	O
non-CS-major	O
students	O
.	O
</s>
<s>
Jens	O
was	O
a	O
member	O
of	O
the	O
Scratch	B-Language
Team	O
before	O
creating	O
Snap	B-Application
!	I-Application
.	O
</s>
<s>
BYOB	B-Application
is	O
still	O
available	O
for	O
downloading	O
.	O
</s>
<s>
The	O
source	O
code	O
of	O
Snap	B-Application
!	I-Application
</s>
<s>
is	O
Affero	O
General	O
Public	O
License	O
(	O
AGPL	O
)	O
licensed	O
and	O
is	O
hosted	O
on	O
GitHub	B-Application
.	O
</s>
<s>
Snap	B-Application
!	I-Application
</s>
<s>
is	O
implemented	O
in	O
JavaScript	B-Language
using	O
an	O
HTML5	B-Application
Canvas	O
application	B-Application
programming	I-Application
interface	I-Application
(	O
API	B-Application
)	O
,	O
and	O
because	O
of	O
that	O
it	O
runs	O
on	O
the	O
major	O
web-browsers	O
on	O
Windows	B-Application
,	O
iOS	B-Application
,	O
OS	B-Operating_System
X	I-Operating_System
and	O
Linux	B-Application
devices	O
.	O
</s>
<s>
Snap	B-Application
!	I-Application
</s>
<s>
has	O
been	O
recognized	O
by	O
the	O
Logo	B-Device
Foundation	O
,	O
and	O
reviewed	O
in	O
an	O
online	O
magazine	O
for	O
programmers	O
.	O
</s>
<s>
As	O
of	O
December	O
2014	O
,	O
100	O
New	O
York	O
City	O
(	O
NYC	O
)	O
high	O
schools	O
will	O
introduce	O
University	O
of	O
California	O
,	O
Berkeley	O
's	O
“	O
Beauty	O
and	O
Joy	O
of	O
Computing	O
”	O
as	O
a	O
new	O
AP	O
Computer	B-General_Concept
Science	I-General_Concept
Principles	O
course	O
starting	O
in	O
2015	O
,	O
using	O
Snap	B-Application
!	I-Application
.	O
</s>
<s>
Jens	O
and	O
Brian	O
received	O
the	O
National	O
Technology	O
Leadership	O
Summit	O
(	O
NTLS	O
)	O
2020	O
Educational	B-Language
Leadership	O
Award	O
for	O
lifetime	O
achievement	O
based	O
in	O
part	O
on	O
Snap	B-Application
!	I-Application
</s>
