<s>
The	O
Gopher	B-Protocol
protocol	I-Protocol
(	O
)	O
is	O
a	O
communication	O
protocol	O
designed	O
for	O
distributing	O
,	O
searching	O
,	O
and	O
retrieving	O
documents	O
in	O
Internet	B-Protocol
Protocol	I-Protocol
networks	O
.	O
</s>
<s>
The	O
design	O
of	O
the	O
Gopher	B-Protocol
protocol	I-Protocol
and	O
user	O
interface	O
is	O
menu-driven	O
,	O
and	O
presented	O
an	O
alternative	O
to	O
the	O
World	O
Wide	O
Web	O
in	O
its	O
early	O
stages	O
,	O
but	O
ultimately	O
fell	O
into	O
disfavor	O
,	O
yielding	O
to	O
HTTP	B-Protocol
.	I-Protocol
</s>
<s>
The	O
Gopher	B-Protocol
ecosystem	O
is	O
often	O
regarded	O
as	O
the	O
effective	O
predecessor	O
of	O
the	O
World	O
Wide	O
Web	O
.	O
</s>
<s>
The	O
Gopher	B-Protocol
protocol	I-Protocol
was	O
invented	O
by	O
a	O
team	O
led	O
by	O
Mark	O
P	O
.	O
McCahill	O
at	O
the	O
University	O
of	O
Minnesota	O
.	O
</s>
<s>
More	O
recent	O
Gopher	B-Protocol
revisions	O
and	O
graphical	O
clients	O
added	O
support	O
for	O
multimedia	O
.	O
</s>
<s>
Gopher	B-Protocol
's	O
hierarchical	O
structure	O
provided	O
a	O
platform	O
for	O
the	O
first	O
large-scale	O
electronic	O
library	O
connections	O
.	O
</s>
<s>
The	O
Gopher	B-Protocol
protocol	I-Protocol
is	O
still	O
in	O
use	O
by	O
enthusiasts	O
,	O
and	O
although	O
it	O
has	O
been	O
almost	O
entirely	O
supplanted	O
by	O
the	O
Web	O
,	O
a	O
small	O
population	O
of	O
actively-maintained	O
servers	O
remains	O
.	O
</s>
<s>
Gopher	B-Protocol
system	O
was	O
released	O
in	O
mid-1991	O
by	O
Mark	O
P	O
.	O
McCahill	O
,	O
Farhad	O
Anklesaria	O
,	O
Paul	O
Lindner	O
,	O
Daniel	O
Torrey	O
,	O
and	O
Bob	O
Alberti	O
of	O
the	O
University	O
of	O
Minnesota	O
in	O
the	O
United	O
States	O
.	O
</s>
<s>
Gopher	B-Protocol
combines	O
document	O
hierarchies	O
with	O
collections	O
of	O
services	O
,	O
including	O
WAIS	B-Protocol
,	O
the	O
Archie	B-Protocol
and	O
Veronica	B-Protocol
search	O
engines	O
,	O
and	O
gateways	O
to	O
other	O
information	O
systems	O
such	O
as	O
File	B-Protocol
Transfer	I-Protocol
Protocol	I-Protocol
(	O
FTP	O
)	O
and	O
Usenet	B-Application
.	O
</s>
<s>
The	O
general	O
interest	O
in	O
campus-wide	O
information	O
systems	O
(	O
CWISs	O
)	O
in	O
higher	O
education	O
at	O
the	O
time	O
,	O
and	O
the	O
ease	O
of	O
setup	O
of	O
Gopher	B-Protocol
servers	O
to	O
create	O
an	O
instant	O
CWIS	O
with	O
links	O
to	O
other	O
sites	O
 '	O
online	O
directories	B-Application
and	O
resources	O
,	O
were	O
the	O
factors	O
contributing	O
to	O
Gopher	B-Protocol
's	O
rapid	O
adoption	O
.	O
</s>
<s>
The	O
name	O
was	O
coined	O
by	O
Anklesaria	O
as	O
a	O
play	O
on	O
several	O
meanings	O
of	O
the	O
word	O
"	O
gopher	B-Protocol
"	O
.	O
</s>
<s>
The	O
University	O
of	O
Minnesota	O
mascot	O
is	O
the	O
gopher	B-Protocol
,	O
a	O
gofer	B-Application
is	O
an	O
assistant	O
who	O
"	O
goes	O
for	O
"	O
things	O
,	O
and	O
a	O
gopher	B-Protocol
burrows	O
through	O
the	O
ground	O
to	O
reach	O
a	O
desired	O
location	O
.	O
</s>
<s>
The	O
World	O
Wide	O
Web	O
was	O
in	O
its	O
infancy	O
in	O
1991	O
,	O
and	O
Gopher	B-Protocol
services	O
quickly	O
became	O
established	O
.	O
</s>
<s>
By	O
the	O
late	O
1990s	O
,	O
Gopher	B-Protocol
had	O
ceased	O
expanding	O
.	O
</s>
<s>
Several	O
factors	O
contributed	O
to	O
Gopher	B-Protocol
's	O
stagnation	O
:	O
</s>
<s>
In	O
February	O
1993	O
,	O
the	O
University	O
of	O
Minnesota	O
announced	O
that	O
it	O
would	O
charge	O
licensing	O
fees	O
for	O
the	O
use	O
of	O
its	O
implementation	O
of	O
the	O
Gopher	B-Protocol
server	O
.	O
</s>
<s>
Gopher	B-Protocol
expansion	O
stagnated	O
,	O
to	O
the	O
advantage	O
of	O
the	O
World	O
Wide	O
Web	O
,	O
to	O
which	O
CERN	O
disclaimed	O
ownership	O
.	O
</s>
<s>
In	O
September	O
2000	O
,	O
the	O
University	O
of	O
Minnesota	O
re-licensed	O
its	O
Gopher	B-Protocol
software	O
under	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
.	O
</s>
<s>
Gopher	B-Protocol
client	I-Protocol
functionality	O
was	O
quickly	O
duplicated	O
by	O
the	O
early	O
Mosaic	B-Application
web	I-Application
browser	I-Application
,	O
which	O
subsumed	O
its	O
protocol	O
.	O
</s>
<s>
Gopher	B-Protocol
has	O
a	O
more	O
rigid	O
structure	O
than	O
the	O
free-form	O
HTML	B-Language
of	O
the	O
Web	O
.	O
</s>
<s>
Every	O
Gopher	B-Protocol
document	O
has	O
a	O
defined	O
format	O
and	O
type	O
,	O
and	O
the	O
typical	O
user	O
navigates	O
through	O
a	O
single	O
server-defined	O
menu	O
system	O
to	O
get	O
to	O
a	O
particular	O
document	O
.	O
</s>
<s>
Gopher	B-Protocol
remains	O
in	O
active	O
use	O
by	O
its	O
enthusiasts	O
,	O
and	O
there	O
have	O
been	O
attempts	O
to	O
revive	O
Gopher	B-Protocol
on	O
modern	O
platforms	O
and	O
mobile	O
devices	O
.	O
</s>
<s>
,	O
there	O
remained	O
about	O
160	O
gopher	B-Protocol
servers	O
indexed	O
by	O
Veronica-2	B-Protocol
,	O
reflecting	O
a	O
slow	O
growth	O
from	O
2007	O
when	O
there	O
were	O
fewer	O
than	O
100	O
.	O
</s>
<s>
On	O
these	O
servers	O
Veronica	B-Protocol
indexed	O
approximately	O
2.5	O
million	O
unique	O
selectors	O
.	O
</s>
<s>
A	O
snapshot	O
of	O
Gopherspace	B-Protocol
in	O
2007	O
circulated	O
on	O
BitTorrent	B-Protocol
and	O
was	O
still	O
available	O
in	O
2010	O
.	O
</s>
<s>
Due	O
to	O
the	O
simplicity	O
of	O
the	O
Gopher	B-Protocol
protocol	I-Protocol
,	O
setting	O
up	O
new	O
servers	O
or	O
adding	O
Gopher	B-Protocol
support	O
to	O
browsers	O
is	O
often	O
done	O
in	O
a	O
tongue-in-cheek	O
manner	O
,	O
principally	O
on	O
April	O
Fools	O
 '	O
Day	O
.	O
</s>
<s>
In	O
November	O
2014	O
Veronica	B-Protocol
indexed	O
144	O
gopher	B-Protocol
servers	O
,	O
reflecting	O
a	O
small	O
drop	O
from	O
2012	O
,	O
but	O
within	O
these	O
servers	O
Veronica	B-Protocol
indexed	O
approximately	O
3million	O
unique	O
selectors	O
.	O
</s>
<s>
In	O
March	O
2016	O
Veronica	B-Protocol
indexed	O
135	O
gopher	B-Protocol
servers	O
,	O
within	O
which	O
it	O
indexed	O
approximately	O
4million	O
unique	O
selectors	O
.	O
</s>
<s>
In	O
March	O
2017	O
Veronica	B-Protocol
indexed	O
133	O
gopher	B-Protocol
servers	O
,	O
within	O
which	O
it	O
indexed	O
approximately	O
4.9million	O
unique	O
selectors	O
.	O
</s>
<s>
In	O
May	O
2018	O
Veronica	B-Protocol
indexed	O
260	O
gopher	B-Protocol
servers	O
,	O
within	O
which	O
it	O
indexed	O
approximately	O
3.7million	O
unique	O
selectors	O
.	O
</s>
<s>
In	O
May	O
2019	O
Veronica	B-Protocol
indexed	O
320	O
gopher	B-Protocol
servers	O
,	O
within	O
which	O
it	O
indexed	O
approximately	O
4.2million	O
unique	O
selectors	O
.	O
</s>
<s>
In	O
January	O
2020	O
Veronica	B-Protocol
indexed	O
395	O
gopher	B-Protocol
servers	O
,	O
within	O
which	O
it	O
indexed	O
approximately	O
4.5million	O
unique	O
selectors	O
.	O
</s>
<s>
In	O
February	O
2021	O
Veronica	B-Protocol
indexed	O
361	O
gopher	B-Protocol
servers	O
,	O
within	O
which	O
it	O
indexed	O
approximately	O
6million	O
unique	O
selectors	O
.	O
</s>
<s>
In	O
February	O
2022	O
Veronica	B-Protocol
indexed	O
325	O
gopher	B-Protocol
servers	O
,	O
within	O
which	O
it	O
indexed	O
approximately	O
5million	O
unique	O
selectors	O
.	O
</s>
<s>
The	O
conceptualization	O
of	O
knowledge	O
in	O
"	O
Gopher	B-Protocol
space	I-Protocol
"	O
or	O
a	O
"	O
cloud	O
"	O
as	O
specific	O
information	O
in	O
a	O
particular	O
file	O
,	O
and	O
the	O
prominence	O
of	O
the	O
FTP	O
,	O
influenced	O
the	O
technology	O
and	O
the	O
resulting	O
functionality	O
of	O
Gopher	B-Protocol
.	O
</s>
<s>
Gopher	B-Protocol
is	O
designed	O
to	O
function	O
and	O
to	O
appear	O
much	O
like	O
a	O
mountable	O
read-only	O
global	O
network	B-Protocol
file	I-Protocol
system	I-Protocol
(	O
and	O
software	O
,	O
such	O
as	O
,	O
is	O
available	O
that	O
can	O
actually	O
mount	O
a	O
Gopher	B-Protocol
server	O
as	O
a	O
FUSE	B-Application
resource	O
)	O
.	O
</s>
<s>
At	O
a	O
minimum	O
,	O
whatever	O
can	O
be	O
done	O
with	O
data	O
files	O
on	O
a	O
CD-ROM	B-Device
,	O
can	O
be	O
done	O
on	O
Gopher	B-Protocol
.	O
</s>
<s>
A	O
Gopher	B-Protocol
system	O
consists	O
of	O
a	O
series	O
of	O
hierarchical	O
hyperlinkable	O
menus	O
.	O
</s>
<s>
Similar	O
to	O
a	O
file	O
on	O
a	O
Web	O
server	O
,	O
a	O
file	O
on	O
a	O
Gopher	B-Protocol
server	O
can	O
be	O
linked	O
to	O
as	O
a	O
menu	O
item	O
from	O
any	O
other	O
Gopher	B-Protocol
server	O
.	O
</s>
<s>
Many	O
servers	O
take	O
advantage	O
of	O
this	O
inter-server	O
linking	O
to	O
provide	O
a	O
directory	B-Application
of	O
other	O
servers	O
that	O
the	O
user	O
can	O
access	O
.	O
</s>
<s>
The	O
Gopher	B-Protocol
protocol	I-Protocol
was	O
first	O
described	O
in	O
.	O
</s>
<s>
IANA	O
has	O
assigned	O
TCP	B-Protocol
port	I-Protocol
70	O
to	O
the	O
Gopher	B-Protocol
protocol	I-Protocol
.	O
</s>
<s>
First	O
,	O
the	O
client	O
establishes	O
a	O
TCP	B-Protocol
connection	O
with	O
the	O
server	O
on	O
port	B-Protocol
70	O
,	O
the	O
standard	O
gopher	B-Protocol
port	B-Protocol
.	O
</s>
<s>
If	O
the	O
item	O
selector	O
were	O
an	O
empty	O
line	O
,	O
the	O
default	O
directory	B-Application
would	O
be	O
selected	O
.	O
</s>
<s>
Because	O
of	O
the	O
simplicity	O
of	O
the	O
Gopher	B-Protocol
protocol	I-Protocol
,	O
tools	O
such	O
as	O
netcat	B-Protocol
make	O
it	O
possible	O
to	O
download	O
Gopher	B-Protocol
content	O
easily	O
from	O
the	O
command	O
line	O
:	O
</s>
<s>
The	O
protocol	O
is	O
also	O
supported	O
by	O
cURL	B-Language
as	O
of	O
7.21.2-DEV	O
.	O
</s>
<s>
Gopher	B-Protocol
menu	O
items	O
are	O
defined	O
by	O
lines	O
of	O
tab-separated	B-Protocol
values	I-Protocol
in	O
a	O
text	B-General_Concept
file	I-General_Concept
.	O
</s>
<s>
As	O
the	O
source	O
code	O
to	O
a	O
gopher	B-Protocol
menu	O
,	O
a	O
gophermap	O
is	O
roughly	O
analogous	O
to	O
an	O
HTML	B-Language
file	I-Language
for	O
a	O
web	O
page	O
.	O
</s>
<s>
Each	O
tab-separated	O
line	O
(	O
called	O
a	O
selector	O
line	O
)	O
gives	O
the	O
client	B-Protocol
software	I-Protocol
a	O
description	O
of	O
the	O
menu	O
item	O
:	O
what	O
it	O
is	O
,	O
what	O
it	O
is	O
called	O
,	O
and	O
where	O
it	O
leads	O
to	O
.	O
</s>
<s>
Gopher	B-Protocol
's	O
item	O
types	O
are	O
a	O
more	O
basic	O
precursor	O
to	O
the	O
media	B-Application
type	I-Application
system	O
used	O
by	O
the	O
Web	O
and	O
email	O
attachments	O
.	O
</s>
<s>
The	O
item	O
type	O
is	O
followed	O
by	O
the	O
user	O
display	O
string	O
(	O
a	O
description	O
or	O
label	O
that	O
represents	O
the	O
item	O
in	O
the	O
menu	O
)	O
;	O
the	O
selector	O
(	O
a	O
path	B-Application
or	O
other	O
string	O
for	O
the	O
resource	O
on	O
the	O
server	O
)	O
;	O
the	O
hostname	O
(	O
the	O
domain	O
name	O
or	O
IP	B-Protocol
address	I-Protocol
of	O
the	O
server	O
)	O
,	O
and	O
the	O
network	B-Protocol
port	I-Protocol
.	O
</s>
<s>
All	O
lines	O
in	O
a	O
gopher	B-Protocol
menu	O
are	O
terminated	O
by	O
"	O
CR	O
+	O
LF	O
"	O
.	O
</s>
<s>
Example	O
of	O
a	O
selector	O
line	O
in	O
a	O
menu	O
source	O
:	O
The	O
following	O
selector	O
line	O
generates	O
a	O
link	O
to	O
the	O
"	O
/home	O
"	O
directory	B-Application
at	O
the	O
subdomain	B-Protocol
gopher.floodgap.com,	O
on	O
port	B-Protocol
70	O
.	O
</s>
<s>
The	O
item	O
type	O
of	O
indicates	O
that	O
the	O
linked	O
resource	O
is	O
a	O
Gopher	B-Protocol
menu	O
itself	O
.	O
</s>
<s>
In	O
a	O
Gopher	B-Protocol
menu	O
's	O
source	O
code	O
,	O
a	O
one-character	O
code	O
indicates	O
what	O
kind	O
of	O
content	O
the	O
client	O
should	O
expect	O
.	O
</s>
<s>
The	O
technical	O
specification	O
for	O
Gopher	B-Protocol
,	O
,	O
defines	O
14	O
item	O
types	O
.	O
</s>
<s>
The	O
later	O
gopher+	O
specification	O
defined	O
an	O
additional	O
3	O
types	O
.	O
</s>
<s>
Item	O
type	O
is	O
an	O
error	B-Application
code	I-Application
for	O
exception	B-General_Concept
handling	I-General_Concept
.	O
</s>
<s>
Gopher	B-Protocol
client	I-Protocol
authors	O
improvised	O
item	O
types	O
(	O
HTML	B-Language
)	O
,	O
(	O
informational	O
message	O
)	O
,	O
and	O
(	O
sound	O
file	O
)	O
after	O
the	O
publication	O
of	O
RFC	O
1436	O
.	O
</s>
<s>
Browsers	O
like	O
Netscape	B-Protocol
Navigator	I-Protocol
and	O
early	O
versions	O
of	O
Microsoft	B-Application
Internet	I-Application
Explorer	I-Application
would	O
prepend	O
the	O
item	O
type	O
code	O
to	O
the	O
selector	O
as	O
described	O
in	O
,	O
so	O
that	O
the	O
type	O
of	O
the	O
gopher	B-Protocol
item	O
could	O
be	O
determined	O
by	O
the	O
url	O
itself	O
.	O
</s>
<s>
Most	O
gopher	B-Protocol
browsers	O
still	O
available	O
,	O
use	O
these	O
prefixes	O
in	O
their	O
urls	O
.	O
</s>
<s>
colspan	O
=	O
"	O
2	O
"	O
Text	B-General_Concept
file	I-General_Concept
Gopher	B-Protocol
submenu	O
CCSO	B-Protocol
Nameserver	I-Protocol
Error	B-Application
code	I-Application
returned	O
by	O
a	O
Gopher	B-Protocol
server	O
to	O
indicate	O
failure	O
BinHex-encoded	O
file	O
(	O
primarily	O
for	O
Macintosh	B-Device
computers	O
)	O
DOS	B-Device
file	O
uuencoded	B-Device
file	O
Gopher	B-Protocol
full-text	B-Application
search	I-Application
Telnet	B-Protocol
Binary	O
file	O
Mirror	O
or	O
alternate	O
server	O
(	O
for	O
load	B-Application
balancing	I-Application
or	O
in	O
case	O
of	O
primary	O
server	O
downtime	O
)	O
GIF	O
file	O
Image	O
file	O
Telnet	B-Protocol
3270	O
colspan	O
=	O
"	O
2	O
"	O
Bitmap	O
image	O
Movie	B-General_Concept
file	I-General_Concept
Sound	O
file	O
colspan	O
=	O
"	O
2	O
"	O
d	O
Doc	O
.	O
</s>
<s>
Seen	O
used	O
alongside	O
PDF	B-Application
's	O
and	O
.DOC	O
'	O
s	O
h	O
HTML	B-Language
file	I-Language
i	O
Informational	O
message	O
,	O
widely	O
used	O
.	O
</s>
<s>
Here	O
is	O
an	O
example	O
gopher	B-Protocol
session	O
where	O
the	O
user	O
requires	O
a	O
gopher	B-Protocol
menu	O
(	O
on	O
the	O
first	O
line	O
)	O
:	O
</s>
<s>
The	O
gopher	B-Protocol
menu	O
sent	O
back	O
from	O
the	O
server	O
,	O
is	O
a	O
sequence	O
of	O
lines	O
each	O
of	O
which	O
describes	O
an	O
item	O
that	O
can	O
be	O
retrieved	O
.	O
</s>
<s>
Most	O
clients	O
will	O
display	O
these	O
as	O
hypertext	O
links	O
,	O
and	O
so	O
allow	O
the	O
user	O
to	O
navigate	O
through	O
gopherspace	B-Protocol
by	O
following	O
the	O
links	O
.	O
</s>
<s>
This	O
menu	O
includes	O
a	O
text	O
resource	O
(	O
itemtype	O
on	O
the	O
third	O
line	O
)	O
,	O
multiple	O
links	O
to	O
submenus	O
(	O
itemtype	O
,	O
on	O
the	O
second	O
line	O
as	O
well	O
as	O
lines	O
4-6	O
)	O
and	O
a	O
non-standard	O
information	O
message	O
(	O
from	O
line	O
7	O
on	O
)	O
,	O
broken	O
down	O
to	O
multiple	O
lines	O
by	O
providing	O
dummy	O
values	O
for	O
selector	O
,	O
host	O
and	O
port	B-Protocol
.	O
</s>
