<s>
FrontDoor	B-Protocol
was	O
one	O
of	O
the	O
most	O
popular	O
mailers	O
in	O
the	O
FidoNet-compatible	O
networks	O
in	O
the	O
1990s	O
,	O
acting	O
as	O
the	O
physical	O
representation	O
of	O
the	O
written	O
network	O
node	O
connection	O
and	O
mail	O
handling	O
standards	O
.	O
</s>
<s>
It	O
was	O
an	O
MS-DOS-based	O
product	O
(	O
also	O
available	O
as	O
shareware	B-License
)	O
written	O
by	O
Joaquim	O
Homrighausen	O
(	O
alias	O
JoHo	O
)	O
.	O
</s>
<s>
The	O
FrontDoor	B-Protocol
system	O
contained	O
a	O
Mailer	O
,	O
an	O
Editor	O
,	O
a	O
Terminal	O
,	O
a	O
serial	B-Protocol
port	I-Protocol
device	B-Application
driver	I-Application
and	O
configuration	O
utilities	O
.	O
</s>
<s>
FrontDoor	B-Protocol
was	O
first	O
released	O
in	O
1986	O
.	O
</s>
<s>
The	O
task	O
of	O
mailers	O
,	O
the	O
main	O
task	O
of	O
the	O
first	O
FrontDoor	B-Protocol
release	O
,	O
was	O
to	O
accept	O
a	O
phone	O
call	O
for	O
a	O
BBS	B-Application
/	O
FidoNet	O
node	O
system	O
;	O
differentiating	O
between	O
human	O
and	O
machine	O
calls	O
(	O
sending	O
the	O
humans	O
to	O
the	O
BBS	B-Application
while	O
handling	O
all	O
other	O
cases	O
)	O
and	O
if	O
the	O
other	O
end	O
supported	O
the	O
same	O
protocol	O
started	O
a	O
conversation	O
about	O
handling	O
whatever	O
packets	O
had	O
to	O
be	O
exchanged	O
,	O
and	O
calling	O
external	O
programs	O
to	O
handle	O
the	O
traffic	O
.	O
</s>
<s>
Originally	O
FrontDoor	B-Protocol
was	O
a	O
small	O
utility	O
to	O
handle	O
incoming	O
calls	O
,	O
written	O
in	O
1986	O
.	O
</s>
<s>
Peter	O
Adenauer	O
of	O
AMS	O
Applied	O
Micro	O
Systems	O
,	O
Inc	O
.	O
of	O
Miami	O
,	O
Florida	O
asked	O
Homrighausen	O
in	O
1987	O
to	O
leave	O
his	O
job	O
at	O
Ericsson	O
and	O
come	O
to	O
the	O
USA	O
and	O
start	O
developing	O
a	O
commercial	O
product	O
based	O
on	O
FrontDoor	B-Protocol
with	O
Peter	O
Stewart	O
.	O
</s>
<s>
FrontDoor	B-Protocol
continued	O
its	O
life	O
as	O
shareware	B-License
as	O
well	O
as	O
a	O
commercial	O
product	O
;	O
the	O
current	O
versions	O
are	O
2.26	O
(	O
DOS+	O
OS/2	B-Application
shareware	B-License
)	O
and	O
2.32.mL	O
(	O
DOS+	O
OS/2	B-Application
multiline	O
commercial	O
)	O
.	O
</s>
<s>
As	O
of	O
September	O
2017	O
,	O
it	O
is	O
still	O
unclear	O
as	O
to	O
which	O
platforms	O
the	O
re-booted	O
FrontDoor	B-Protocol
project	O
will	O
run	O
on	O
.	O
</s>
<s>
FrontDoor	B-Protocol
runs	O
under	O
DOS	B-Device
and	O
OS/2	B-Application
as	O
well	O
as	O
under	O
most	O
DOS-based	O
multi-tasking	O
environment	O
(	O
like	O
Windows	O
,	O
DESQview	B-Operating_System
,	O
DoubleDOS	B-Device
,	O
and	O
more	O
)	O
.	O
</s>
<s>
File	O
transfer	O
protocols	O
supported	O
by	O
FrontDoor	B-Protocol
are	O
Zmodem	B-Device
,	O
Zmodem/CRC32	O
,	O
Telink	O
,	O
SEAlink	B-Protocol
,	O
SEAlink	B-Protocol
Overdrive	O
,	O
and	O
Xmodem/CRC	O
.	O
</s>
<s>
FrontDoor	B-Protocol
consists	O
of	O
:	O
</s>
<s>
FrontDoor	B-Protocol
features	O
:	O
</s>
