<s>
Lispkit	B-Language
Lisp	I-Language
is	O
a	O
lexically	O
scoped	O
,	O
purely	B-Application
functional	I-Application
subset	O
of	O
Lisp	B-Language
(	O
"	O
Pure	O
Lisp	B-Language
"	O
)	O
developed	O
as	O
a	O
testbed	O
for	O
functional	B-Language
programming	I-Language
concepts	O
.	O
</s>
<s>
An	O
SECD	O
machine-based	O
implementation	O
written	O
in	O
an	O
ALGOL	B-Language
variant	O
was	O
published	O
by	O
the	O
developer	O
Peter	O
Henderson	O
in	O
1980	O
.	O
</s>
<s>
The	O
compiler	B-Language
and	O
virtual	B-Architecture
machine	I-Architecture
are	O
highly	O
portable	O
and	O
as	O
a	O
result	O
have	O
been	O
implemented	O
on	O
many	O
machines	O
.	O
</s>
