<s>
Gemini	B-Protocol
is	O
an	O
application-layer	B-Application
internet	O
communication	O
protocol	O
for	O
accessing	O
remote	O
documents	O
,	O
similar	O
to	O
the	O
Hypertext	B-Protocol
Transfer	I-Protocol
Protocol	I-Protocol
(	O
HTTP	B-Protocol
)	O
and	O
Gopher	B-Protocol
.	O
</s>
<s>
The	O
Gemini	B-Protocol
project	O
was	O
started	O
in	O
June	O
2019	O
by	O
Solderpunk	O
.	O
</s>
<s>
According	O
to	O
Solderpunk	O
's	O
FAQ	O
,	O
Gemini	B-Protocol
is	O
not	O
intended	O
to	O
replace	O
Gopher	B-Protocol
or	O
HTTP	B-Protocol
,	O
but	O
to	O
co-exist	O
with	O
them	O
.	O
</s>
<s>
Much	O
of	O
the	O
development	O
happened	O
on	O
the	O
Gemini	B-Protocol
mailing	O
list	O
until	O
the	O
list	O
disappeared	O
end	O
of	O
2021	O
due	O
to	O
a	O
hardware	O
issue	O
.	O
</s>
<s>
The	O
creation	O
of	O
the	O
Usenet	B-Application
newsgroup	O
comp.infosystems.gemini	O
in	O
October	O
2021	O
was	O
the	O
first	O
new	O
newsgroup	O
in	O
the	O
Big	B-Architecture
Eight	I-Architecture
hierarchy	O
in	O
eight	O
years	O
.	O
</s>
<s>
The	O
Gemini	B-Protocol
specification	O
defines	O
both	O
the	O
Gemini	B-Protocol
protocol	O
and	O
a	O
native	O
file	O
format	O
for	O
that	O
protocol	O
,	O
analogous	O
to	O
HTML	B-Language
for	O
HTTP	B-Protocol
,	O
known	O
as	O
"	O
gemtext	O
"	O
.	O
</s>
<s>
The	O
design	O
is	O
inspired	O
by	O
Gopher	B-Protocol
,	O
but	O
with	O
modernisation	O
such	O
as	O
mandatory	O
use	O
of	O
Transport	B-Protocol
Layer	I-Protocol
Security	I-Protocol
(	O
TLS	O
)	O
for	O
connections	O
and	O
a	O
hypertext	O
format	O
as	O
native	O
content	B-Application
type	I-Application
.	O
</s>
<s>
Gemini	B-Protocol
is	O
designed	O
within	O
the	O
framework	O
of	O
the	O
Internet	B-Protocol
protocol	I-Protocol
suite	I-Protocol
and	O
like	O
HTTP/S	O
,	O
Gemini	B-Protocol
functions	O
as	O
a	O
request	B-Protocol
–	I-Protocol
response	I-Protocol
protocol	O
in	O
the	O
client	O
–	O
server	O
computing	O
model	O
.	O
</s>
<s>
A	O
Gemini	B-Protocol
server	O
should	O
listen	O
on	O
TCP	O
port	O
1965	O
.	O
</s>
<s>
A	O
Gemini	B-Protocol
browser	O
,	O
for	O
example	O
,	O
may	O
be	O
the	O
client	O
and	O
an	O
application	O
running	O
on	O
a	O
computer	O
hosting	B-Device
a	O
Gemini	B-Protocol
site	O
may	O
be	O
the	O
server	O
.	O
</s>
<s>
The	O
client	O
sends	O
a	O
Gemini	B-Protocol
request	O
message	O
to	O
the	O
server	O
,	O
and	O
the	O
server	O
sends	O
back	O
a	O
response	O
message	O
.	O
</s>
<s>
Gemini	B-Protocol
uses	O
a	O
separate	O
connection	B-Protocol
to	O
the	O
same	O
server	O
for	O
every	O
resource	O
request	O
.	O
</s>
<s>
Gemini	B-Protocol
mandates	O
the	O
use	O
of	O
TLS	O
with	O
privacy-related	O
features	O
and	O
trust	O
on	O
first	O
use	O
(	O
TOFU	O
)	O
verification	O
being	O
strongly	O
suggested	O
.	O
</s>
<s>
Gemini	B-Protocol
resources	O
are	O
identified	O
and	O
located	O
on	O
the	O
network	O
by	O
Uniform	O
Resource	O
Locators	O
(	O
URLs	O
)	O
,	O
using	O
the	O
URI	O
scheme	O
gemini://	O
.	O
</s>
<s>
A	O
Gemini	B-Protocol
request	O
consists	O
only	O
of	O
such	O
a	O
URL	O
,	O
terminated	O
by	O
CRLF	O
;	O
the	O
header	O
of	O
a	O
Gemini	B-Protocol
response	O
consists	O
of	O
a	O
two-digit	O
status	O
code	O
,	O
a	O
space	O
,	O
and	O
a	O
"	O
meta	O
"	O
field	O
,	O
also	O
terminated	O
by	O
CRLF	O
.	O
</s>
<s>
If	O
the	O
server	O
is	O
successful	O
in	O
finding	O
the	O
requested	O
file	O
,	O
the	O
"	O
meta	O
"	O
field	O
is	O
the	O
MIME	B-Application
type	I-Application
of	O
the	O
returned	O
file	O
and	O
after	O
the	O
header	O
follows	O
the	O
file	O
data	O
.	O
</s>
<s>
Welcome	O
to	O
my	O
Gemini	B-Protocol
capsule	O
.	O
</s>
<s>
As	O
with	O
HTTP	B-Protocol
hypertext	O
,	O
URIs	O
are	O
encoded	O
as	O
hyperlinks	O
to	O
form	O
interlinked	O
hypertext	O
documents	O
in	O
the	O
Gemini	B-Protocol
"	O
web	O
"	O
,	O
which	O
users	O
refer	O
to	O
as	O
Geminispace	O
.	O
</s>
<s>
"	O
Geminispace	O
"	O
denotes	O
the	O
whole	O
of	O
the	O
public	O
resources	O
that	O
are	O
published	O
on	O
the	O
Internet	O
by	O
the	O
Gemini	B-Protocol
community	O
via	O
the	O
Gemini	B-Protocol
protocol	O
.	O
</s>
<s>
Thus	O
,	O
Gemini	B-Protocol
spans	O
an	O
alternative	O
communication	O
web	O
,	O
with	O
hypertext	O
documents	O
,	O
including	O
hyperlinks	O
to	O
other	O
resources	O
easily	O
accessible	O
to	O
the	O
user	O
.	O
</s>
<s>
Geminispace	O
consists	O
of	O
around	O
2300	O
online	O
known	O
Gemini	B-Protocol
appearances	O
(	O
"	O
capsules	O
"	O
)	O
identified	O
by	O
crawling	O
over	O
490,000	O
URIs	O
.	O
</s>
<s>
The	O
Gemini	B-Protocol
software	O
list	O
covers	O
client	O
,	O
server	O
,	O
libraries	O
,	O
and	O
tools	O
.	O
</s>
<s>
Gemini-to-HTTP	O
proxy	B-Application
server	I-Application
gateways	O
such	O
as	O
Mozz.us	O
can	O
be	O
used	O
by	O
web	O
browsers	O
lacking	O
Gemini	B-Protocol
support	O
.	O
</s>
<s>
Gemini	B-Protocol
is	O
praised	O
for	O
its	O
simplicity	O
but	O
criticized	O
for	O
"	O
excluding	O
people	O
who	O
use	O
ordinary	O
web	O
browsers	O
"	O
.	O
</s>
<s>
Gemini	B-Protocol
's	O
usefulness	O
has	O
been	O
said	O
to	O
be	O
"	O
dependent	O
on	O
the	O
kinds	O
of	O
content	O
available	O
on	O
Gemini	B-Protocol
and	O
whether	O
it	O
appeals	O
or	O
not	O
"	O
.	O
</s>
<s>
Stéphane	O
Bortzmeyer	O
has	O
said	O
Gemini	B-Protocol
is	O
retro	O
but	O
with	O
modern	O
features	O
.	O
</s>
