<s>
GeckOS	B-Operating_System
is	O
a	O
multitasking	O
operating	B-General_Concept
system	I-General_Concept
for	O
MOS	B-General_Concept
6502	I-General_Concept
,	O
and	O
compatible	O
processors	O
such	O
as	O
the	O
MOS	B-General_Concept
6510	I-General_Concept
.	O
</s>
<s>
The	O
GeckOS	B-Operating_System
operating	B-General_Concept
system	I-General_Concept
is	O
one	O
of	O
the	O
few	O
successful	O
attempts	O
to	O
implement	O
a	O
Unix-like	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
on	O
the	O
6502	B-General_Concept
architecture	O
.	O
</s>
<s>
The	O
system	O
offers	O
some	O
Unix-like	B-Operating_System
functionality	O
including	O
pre-emptive	O
multitasking	O
,	O
multithreading	O
,	O
semaphores	O
,	O
signals	O
,	O
binary	O
relocation	B-Library
,	O
TCP/IP	B-Protocol
networking	O
via	O
SLIP	B-Protocol
,	O
and	O
a	O
6502	B-General_Concept
standard	B-Library
library	I-Library
.	O
</s>
<s>
GeckOS	B-Operating_System
includes	O
native	O
support	O
for	O
the	O
Commodore	B-Device
PET	I-Device
(	O
32KB	O
and	O
96KB	O
models	O
)	O
,	O
Commodore	O
64	O
and	O
the	O
CS/A65	O
homebrew	O
system	O
.	O
</s>
<s>
Due	O
to	O
the	O
platform	O
independent	O
nature	O
of	O
the	O
kernel	O
code	O
,	O
GeckOS	B-Operating_System
is	O
advertised	O
as	O
an	O
extremely	O
easy	O
OS	O
to	O
port	O
to	O
alternative	O
6502	B-General_Concept
platforms	O
.	O
</s>
<s>
Binary	O
compatibility	O
with	O
the	O
LUnix	B-Operating_System
operating	B-General_Concept
system	I-General_Concept
can	O
be	O
attained	O
when	O
the	O
lib6502	O
shared	O
library	O
is	O
used	O
.	O
</s>
<s>
Due	O
to	O
the	O
small	O
fixed-location	O
stack	O
of	O
the	O
6502	B-General_Concept
,	O
and	O
because	O
an	O
external	O
MMU	B-General_Concept
is	O
rarely	O
provided	O
,	O
multitasking	O
is	O
somewhat	O
limited	O
.	O
</s>
<s>
A	O
webserver	B-Application
is	O
integrated	O
into	O
the	O
SLIP	B-Protocol
daemon	O
.	O
</s>
<s>
While	O
early	O
versions	O
of	O
Unix	O
ran	O
on	O
for	O
example	O
early	O
model	O
PDP-11	B-Device
computers	O
that	O
were	O
comparable	O
to	O
Commodore	O
64	O
in	O
terms	O
of	O
memory	O
and	O
processor	O
performance	O
there	O
were	O
architecture	O
differences	O
in	O
terms	O
of	O
lack	O
of	O
a	O
kernel	O
mode	O
,	O
only	O
3	O
8-bit	O
registers	O
versus	O
eight	O
16-bit	O
general	O
registers	O
,	O
and	O
a	O
fixed	O
stack	O
.	O
</s>
<s>
These	O
architectural	O
limitations	O
make	O
implementing	O
a	O
Unix-like	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
on	O
the	O
6502	B-General_Concept
challenging	O
.	O
</s>
<s>
The	O
possible	O
non-exhaustive	O
list	O
of	O
other	O
viable	O
Unix-like	B-Operating_System
implementations	O
on	O
6502	B-General_Concept
are	O
LUnix	B-Operating_System
,	O
Asterix	O
(	O
Chris	O
Baird	O
)	O
and	O
ACE	O
(	O
Chris	O
"	O
Polar	O
"	O
Baird	O
)	O
.	O
</s>
<s>
GeckOS	B-Operating_System
arguably	O
is	O
more	O
complete	O
in	O
some	O
respects	O
,	O
with	O
ACE	O
being	O
stronger	O
in	O
terms	O
of	O
standard	O
Unix	O
utilities	O
but	O
weaker	O
in	O
the	O
operating	B-General_Concept
system	I-General_Concept
area	O
.	O
</s>
