<s>
A	O
concatenative	B-Language
programming	I-Language
language	I-Language
is	O
a	O
point-free	B-Application
computer	O
programming	O
language	O
in	O
which	O
all	O
expressions	O
denote	O
functions	O
,	O
and	O
the	O
juxtaposition	O
of	O
expressions	O
denotes	O
function	B-Application
composition	I-Application
.	O
</s>
<s>
Concatenative	B-Language
programming	I-Language
replaces	O
function	B-Algorithm
application	I-Algorithm
,	O
which	O
is	O
common	O
in	O
other	O
programming	O
styles	O
,	O
with	O
function	B-Application
composition	I-Application
as	O
the	O
default	O
way	O
to	O
build	O
subroutines	O
.	O
</s>
<s>
is	O
...	O
written	O
in	O
a	O
concatenative	B-Language
language	I-Language
as	O
a	O
sequence	O
of	O
functions	O
:	O
</s>
<s>
Functions	O
and	O
procedures	O
written	O
in	O
concatenative	O
style	O
are	O
not	O
value	B-Application
level	I-Application
,	O
i.e.	O
</s>
<s>
they	O
typically	O
do	O
not	O
represent	O
the	O
data	B-General_Concept
structures	I-General_Concept
they	O
operate	O
on	O
with	O
explicit	O
names	O
or	O
identifiers	O
.	O
</s>
<s>
Instead	O
they	O
are	O
function	O
levela	O
function	O
is	O
defined	O
as	O
a	O
pipeline	B-Operating_System
,	O
or	O
a	O
sequence	O
of	O
operations	O
that	O
take	O
parameters	O
from	O
an	O
implicit	O
data	B-General_Concept
structure	I-General_Concept
upon	O
which	O
all	O
functions	O
operate	O
,	O
and	O
return	O
the	O
function	O
results	O
to	O
that	O
shared	O
structure	O
so	O
that	O
it	O
will	O
be	O
used	O
by	O
the	O
next	O
operator	O
.	O
</s>
<s>
The	O
combination	O
of	O
compositional	O
semantics	B-Application
with	O
a	O
syntax	O
that	O
mirrors	O
such	O
a	O
semantic	O
makes	O
concatenative	B-Language
languages	I-Language
highly	O
amenable	O
to	O
algebraic	O
manipulation	O
of	O
programs	O
;	O
although	O
it	O
may	O
be	O
difficult	O
to	O
write	O
mathematical	O
expressions	O
directly	O
in	O
them	O
.	O
</s>
<s>
Concatenative	B-Language
languages	I-Language
can	O
be	O
implemented	O
efficiently	O
with	O
a	O
stack	B-Application
machine	I-Application
,	O
and	O
are	O
commonly	O
present	O
implicitly	O
in	O
virtual	B-Architecture
machines	I-Architecture
in	O
the	O
form	O
of	O
their	O
instruction	B-General_Concept
sets	I-General_Concept
.	O
</s>
<s>
The	O
properties	O
of	O
concatenative	B-Language
languages	I-Language
are	O
the	O
result	O
of	O
their	O
compositional	O
syntax	O
and	O
semantics	B-Application
:	O
</s>
<s>
The	O
syntax	O
and	O
semantics	B-Application
of	O
concatenative	B-Language
languages	I-Language
form	O
the	O
algebraic	O
structure	O
of	O
a	O
monoid	O
.	O
</s>
<s>
Concatenative	B-Language
languages	I-Language
can	O
be	O
made	O
well-suited	O
to	O
an	O
implementation	O
inspired	O
by	O
linear	O
logic	O
where	O
no	O
garbage	B-General_Concept
is	O
ever	O
generated	O
.	O
</s>
<s>
The	O
first	O
concatenative	B-Language
programming	I-Language
language	I-Language
was	O
Forth	B-Application
,	O
although	O
Joy	B-Application
was	O
the	O
first	O
language	O
to	O
call	O
itself	O
concatenative	O
.	O
</s>
<s>
Other	O
concatenative	B-Language
languages	I-Language
are	O
dc	O
,	O
Factor	B-Application
,	O
Onyx	O
,	O
PostScript	B-Language
,	O
and	O
RPL	B-Device
.	O
</s>
<s>
Most	O
existing	O
concatenative	B-Language
languages	I-Language
are	O
stack-based	B-Language
;	O
this	O
is	O
not	O
a	O
requirement	O
and	O
other	O
models	O
have	O
been	O
proposed	O
.	O
</s>
<s>
Concatenative	B-Language
languages	I-Language
are	O
currently	O
used	O
for	O
embedded	B-Architecture
,	O
desktop	B-Application
,	O
and	O
web	O
programming	O
,	O
as	O
target	B-Application
languages	I-Application
,	O
and	O
for	O
research	O
purposes	O
.	O
</s>
<s>
Most	O
concatenative	B-Language
languages	I-Language
are	O
dynamically	O
typed	O
.	O
</s>
