<s>
Citadel	B-Protocol
is	O
the	O
name	O
of	O
a	O
bulletin	B-Application
board	I-Application
system	I-Application
(	O
BBS	O
)	O
computer	O
program	O
,	O
and	O
of	O
the	O
genre	O
of	O
programs	O
it	O
inspired	O
.	O
</s>
<s>
Citadels	B-Protocol
were	O
notable	O
for	O
their	O
room-based	O
structure	O
(	O
see	O
below	O
)	O
and	O
relatively	O
heavy	O
emphasis	O
on	O
messages	O
and	O
conversation	O
as	O
opposed	O
to	O
gaming	O
and	O
files	O
.	O
</s>
<s>
The	O
first	O
Citadel	B-Protocol
came	O
online	O
in	O
1980	O
with	O
a	O
single	O
300	O
baud	O
modem	O
;	O
eventually	O
many	O
versions	O
of	O
the	O
software	O
,	O
both	O
clones	O
and	O
those	O
descended	O
from	O
the	O
original	O
code	O
base	O
(	O
but	O
all	O
usually	O
called	O
"	O
Citadels	B-Protocol
"	O
)	O
,	O
became	O
popular	O
among	O
BBS	O
callers	O
and	O
sysops	O
,	O
particularly	O
in	O
areas	O
such	O
as	O
the	O
Pacific	O
Northwest	O
,	O
Northern	O
California	O
and	O
Upper	O
Midwest	O
of	O
the	O
United	O
States	O
,	O
where	O
development	O
of	O
the	O
software	O
was	O
ongoing	O
.	O
</s>
<s>
Citadel	B-Protocol
BBSes	B-Application
were	O
most	O
popular	O
in	O
the	O
late	O
1980s	O
and	O
early	O
1990s	O
,	O
but	O
when	O
the	O
Internet	O
became	O
more	O
accessible	O
for	O
online	O
communication	O
,	O
Citadels	B-Protocol
began	O
to	O
decline	O
.	O
</s>
<s>
However	O
,	O
some	O
versions	O
of	O
the	O
software	O
,	O
from	O
small	O
community	O
BBSes	B-Application
to	O
large	O
systems	O
supporting	O
thousands	O
of	O
simultaneous	O
users	O
,	O
are	O
still	O
in	O
use	O
today	O
.	O
</s>
<s>
Citadel	B-Protocol
development	O
has	O
always	O
been	O
collaborative	O
with	O
a	O
strong	O
push	O
to	O
keep	O
the	O
source	O
code	O
in	O
the	O
public	O
domain	O
.	O
</s>
<s>
This	O
makes	O
Citadel	B-Protocol
one	O
of	O
the	O
oldest	O
surviving	O
FOSS	B-License
projects	O
.	O
</s>
<s>
The	O
utilization	O
of	O
a	O
natural	O
metaphor	O
,	O
the	O
concept	O
of	O
rooms	O
devoted	O
to	O
topics	O
,	O
marked	O
Citadel	B-Protocol
's	O
main	O
advancement	O
over	O
previous	O
BBS	O
packages	O
in	O
the	O
area	O
of	O
organization	O
.	O
</s>
<s>
Certain	O
versions	O
of	O
Citadel	B-Protocol
extend	O
the	O
metaphor	O
of	O
rooms	O
with	O
“	O
hallways	O
”	O
and/or	O
“	O
floors	O
,	O
”	O
organizing	O
groups	O
of	O
rooms	O
according	O
to	O
system	O
requirement	O
.	O
</s>
<s>
By	O
contrast	O
,	O
previous	O
bulletin	O
board	O
software	O
emphasized	O
the	O
availability	O
of	O
files	O
,	O
with	O
a	O
single	O
uncoupled	B-Application
message	O
area	O
that	O
could	O
only	O
be	O
read	O
linearly	O
,	O
forward	O
or	O
backward	O
.	O
</s>
<s>
Citadel	B-Protocol
further	O
improved	O
the	O
user	O
experience	O
in	O
the	O
area	O
of	O
command	O
and	O
control	O
.	O
</s>
<s>
Based	O
on	O
Alan	O
Kay	O
’s	O
philosophy	O
of	O
user-interface	O
design	O
,	O
“	O
Simple	O
things	O
should	O
be	O
simple	O
;	O
complex	O
things	O
should	O
be	O
possible	O
,	O
”	O
and	O
influenced	O
by	O
the	O
fact	O
that	O
Citadel	B-Protocol
was	O
developed	O
in	O
an	O
era	O
of	O
300	O
baud	O
modems	O
,	O
the	O
basic	O
and	O
most	O
heavily	O
used	O
commands	O
are	O
accessed	O
via	O
single	O
keystrokes	O
.	O
</s>
<s>
This	O
elegantly	O
small	O
command	O
set	O
made	O
the	O
system	O
so	O
usable	O
that	O
many	O
daily	O
users	O
during	O
Citadel	B-Protocol
’s	O
golden	O
era	O
were	O
never	O
aware	O
that	O
Citadel	B-Protocol
also	O
provided	O
sophisticated	O
capabilities	O
.	O
</s>
<s>
A	O
more	O
complex	O
example	O
might	O
be	O
.Read	O
All	O
rooms	O
Zmodem	B-Device
New	O
messages	O
(	O
.RAZN	O
)	O
,	O
which	O
results	O
in	O
all	O
of	O
the	O
new	O
messages	O
in	O
all	O
of	O
the	O
rooms	O
known	O
to	O
the	O
user	O
being	O
sent	O
to	O
the	O
user	O
via	O
the	O
ZMODEM	B-Device
protocol	O
.	O
</s>
<s>
Filters	O
for	O
users	O
,	O
keyword	O
searches	O
,	O
and	O
other	O
capabilities	O
have	O
been	O
implemented	O
,	O
depending	O
on	O
the	O
version	O
of	O
Citadel	B-Protocol
.	O
</s>
<s>
Citadel	B-Protocol
was	O
originally	O
written	O
for	O
the	O
CP/M	B-Application
operating	I-Application
system	I-Application
in	O
1981	O
by	O
Jeff	O
Prothero	O
,	O
known	O
to	O
the	O
nascent	O
Citadel	B-Protocol
world	O
as	O
Cynbe	O
ru	O
Taren	O
(	O
CrT	O
)	O
.	O
</s>
<s>
Unlike	O
most	O
BASIC-based	O
BBS	O
programs	O
of	O
the	O
time	O
,	O
it	O
was	O
written	O
in	O
a	O
fairly	O
standard	O
dialect	O
of	O
C	O
known	O
as	O
BDS	B-Application
C	I-Application
,	O
a	O
compiler	O
written	O
and	O
distributed	O
by	O
Leor	O
Zolman	O
.	O
</s>
<s>
At	O
this	O
point	O
,	O
the	O
history	O
of	O
Citadel	B-Protocol
becomes	O
complex	O
as	O
many	O
individuals	O
began	O
modifying	O
the	O
source	O
to	O
their	O
own	O
ends	O
,	O
and	O
lacking	O
modern	O
distributed	O
source	O
tracking	O
,	O
innovations	O
were	O
never	O
incorporated	O
into	O
a	O
central	O
source	O
repository	O
,	O
as	O
such	O
a	O
thing	O
did	O
not	O
exist	O
.	O
</s>
<s>
The	O
longest	O
lived	O
fork	O
from	O
the	O
2.10	O
code	O
started	O
in	O
the	O
American	O
Midwest	O
,	O
when	O
Hue	O
White	O
(	O
aka	O
Hue	O
,	O
Jr.	O
)	O
ported	O
the	O
code	O
to	O
MS-DOS	O
and	O
called	O
it	O
Citadel-86	O
(	O
"	O
C-86	O
"	O
)	O
.	O
</s>
<s>
His	O
board	O
,	O
Citadel-86	O
Test	O
System	O
,	O
served	O
not	O
only	O
as	O
a	O
discussion	O
board	O
and	O
distribution	O
center	O
for	O
the	O
software	O
,	O
but	O
also	O
was	O
the	O
focal	O
point	O
for	O
a	O
lively	O
Citadel-86	O
community	O
in	O
the	O
612	O
area	O
code	O
(	O
the	O
Twin	O
Cities	O
)	O
,	O
which	O
at	O
their	O
peak	O
numbered	O
roughly	O
forty	O
systems	O
,	O
and	O
probably	O
more	O
than	O
100	O
over	O
the	O
years	O
.	O
</s>
<s>
Numerous	O
suggestions	O
from	O
sysops	O
and	O
users	O
,	O
both	O
local	O
and	O
national	O
,	O
guided	O
the	O
growth	O
of	O
Citadel-86	O
,	O
including	O
the	O
addition	O
of	O
a	O
network	O
capability	O
as	O
well	O
as	O
enhancements	O
to	O
the	O
command	O
set	O
.	O
</s>
<s>
Hue	O
's	O
contributions	O
were	O
substantial	O
enough	O
that	O
several	O
other	O
porting	O
projects	O
used	O
Citadel-86	O
as	O
source	O
material	O
,	O
such	O
as	O
Asgard-86	O
(	O
MS-DOS	O
)	O
,	O
Macadel	O
(	O
Macintosh	O
)	O
,	O
STadel	O
(	O
Atari	O
ST	O
,	O
fnordadel	O
)	O
,	O
Citadel-68K	O
(	O
Amiga	O
)	O
,	O
and	O
Citadel:K2NE	O
(	O
MS-DOS	O
)	O
,	O
and	O
many	O
of	O
these	O
contributed	O
back	O
to	O
Hue	O
Jr	O
's	O
project	O
.	O
</s>
<s>
Most	O
of	O
these	O
ports	O
were	O
compatible	O
with	O
the	O
growing	O
Citadel-86	O
network	O
(	O
C86Net	O
)	O
.	O
</s>
<s>
An	O
early	O
fork	O
from	O
Citadel-86	O
was	O
DragCit	O
,	O
written	O
by	O
The	O
Dragon	O
.	O
</s>
<s>
DragCit	O
also	O
introduced	O
networking	O
code	O
,	O
but	O
the	O
DragCit	O
network	O
was	O
not	O
generally	O
compatible	O
with	O
the	O
Citadel-86	O
network	O
.	O
</s>
<s>
DragCit	O
forked	O
to	O
several	O
more	O
versions	O
,	O
eventually	O
leading	O
to	O
efforts	O
to	O
merge	O
several	O
code	O
bases	O
under	O
the	O
guidance	O
of	O
Matt	O
Pfleger	O
,	O
Richard	O
Goldfinder	O
,	O
Brent	O
Bottles	O
,	O
Don	O
Kimberlin	O
,	O
and	O
Elisabeth	O
Perrin	O
,	O
the	O
end	O
result	O
being	O
Citadel+	O
,	O
a	O
multiuser	O
capable	O
version	O
of	O
the	O
software	O
,	O
which	O
also	O
included	O
advanced	O
scripting	O
,	O
user	O
control	O
of	O
message	O
displays	O
,	O
and	O
other	O
features	O
.	O
</s>
<s>
Implementations	O
that	O
share	O
the	O
familiar	O
Citadel	B-Protocol
user	O
interface	O
,	O
but	O
are	O
not	O
derived	O
from	O
the	O
original	O
Citadel	B-Protocol
code	O
base	O
,	O
are	O
also	O
common	O
.	O
</s>
<s>
They	O
have	O
ranged	O
from	O
vanity	O
projects	O
such	O
as	O
a	O
Citadel-like	O
control	O
program	O
to	O
control	O
the	O
serial	O
port	O
of	O
an	O
advanced	O
graphing	O
calculator	O
,	O
to	O
full-blown	O
efforts	O
to	O
modernize	O
the	O
Citadel	B-Protocol
interface	O
with	O
modern	O
protocols	O
.	O
</s>
<s>
Some	O
of	O
the	O
more	O
notable	O
ones	O
included	O
Glenn	O
Gorman	O
's	O
TRS-80	B-Device
BASIC	O
implementation	O
called	O
Minibin	O
,	O
a	O
clone	O
of	O
Cit-86	O
intended	O
to	O
run	O
on	O
a	O
Unix	O
running	O
on	O
Motorola	O
processors	O
called	O
Cit/68	O
,	O
and	O
a	O
Unix	O
version	O
,	O
technically	O
called	O
Citadel/UX	B-Protocol
but	O
referred	O
to	O
simply	O
as	O
"	O
Citadel	B-Protocol
"	O
in	O
the	O
mainstream	O
open	O
source	O
community	O
.	O
</s>
<s>
This	O
version	O
of	O
Citadel	B-Protocol
is	O
still	O
being	O
developed	O
,	O
extending	O
the	O
Citadel	B-Protocol
metaphor	O
to	O
enable	O
what	O
its	O
developers	O
call	O
"	O
a	O
messaging	O
and	O
collaboration	B-Application
platform	I-Application
(	O
for	O
)	O
connecting	O
communities	O
of	O
people	O
together	O
"	O
:	O
a	O
groupware	B-Application
platform	O
.	O
</s>
<s>
Several	O
efforts	O
have	O
also	O
been	O
made	O
to	O
present	O
the	O
Citadel	B-Protocol
paradigm	O
as	O
a	O
web	O
service	O
,	O
including	O
Webadel	O
,	O
written	O
by	O
Jarrin	O
Jambik	O
,	O
a	O
former	O
Citadel-86	O
sysop	O
,	O
and	O
Anansi-web	O
,	O
anansi-web.com	O
hosted	O
by	O
former	O
Citadel-86	O
Sysop	O
,	O
Ultravox	O
the	O
Muse	O
.	O
</s>
<s>
The	O
only	O
current	O
actively	O
developed	O
web-enabled	O
Citadels	B-Protocol
are	O
Citadel/UX	B-Protocol
and	O
PenguinCit	O
,	O
a	O
PHP-based	O
Citadel	B-Protocol
.	O
</s>
<s>
Name/site	O
Description	O
telnet	B-Protocol
ssh	B-Protocol
with	O
login	O
=	O
bbs	O
KaraNet	O
BBS	O
The	O
largest	O
Austrian	O
BBS	O
(	O
DOC	O
)	O
.	O
</s>
<s>
ISCABBS.com	O
Started	O
in	O
1989	O
and	O
still	O
an	O
active	O
DOC	O
(	O
Dave	O
's	O
Own	O
Citadel	B-Protocol
)	O
BBS	O
.	O
</s>
<s>
Slumberland	O
One	O
of	O
the	O
last	O
remaining	O
Citadel+	O
(	O
established	O
in	O
1991	O
)	O
(	O
appears	O
to	O
be	O
down	O
as	O
of	O
2018sep17	O
)	O
.	O
</s>
<s>
BBS	O
The	O
flagship	O
site	O
of	O
modern	O
Citadel	B-Protocol
systems	O
,	O
established	O
in	O
1988	O
.	O
</s>
<s>
Smashbot	O
's	O
Citadel	B-Protocol
A	O
"	O
modern	O
"	O
Citadel	B-Protocol
931	O
,	O
always	O
in	O
development	O
.	O
</s>
<s>
The	O
Sanatarium	O
BBS	O
An	O
original	O
916	O
Citadel	B-Protocol
now	O
running	O
931	O
,	O
The	O
Sanitarium/The	O
Amiga	O
Archives	O
began	O
in	O
Sacramento	O
,	O
California	O
.	O
</s>
