<s>
DOS	B-Application
Navigator	I-Application
(	O
DN	B-Application
)	O
is	O
an	O
orthodox	O
file	O
manager	O
for	O
DOS	B-Device
,	O
OS/2	B-Application
,	O
and	O
Windows	B-Application
.	O
</s>
<s>
DOS	B-Application
Navigator	I-Application
is	O
an	O
influential	O
early	O
implementation	O
of	O
orthodox	O
file	O
manager	O
(	O
OFM	O
)	O
.	O
</s>
<s>
By	O
implementing	O
three	O
additional	O
types	O
of	O
virtual	B-Application
file	I-Application
systems	I-Application
(	O
VFS	O
)	O
:	O
XTree	B-Application
,	O
Briefcase	O
and	O
list-based	O
,	O
DN	B-Application
launched	O
a	O
new	O
generation	O
of	O
OFMs	O
.	O
</s>
<s>
The	O
initial	O
version	O
of	O
DN	B-Application
I	O
(	O
v	O
0.90	O
)	O
was	O
released	O
in	O
1991	O
,	O
and	O
written	O
by	O
Stefan	O
Tanurkov	O
,	O
Andrew	O
Zabolotny	O
and	O
Sergey	O
Melnik	O
(	O
all	O
from	O
Chișinău	O
,	O
Moldova	O
)	O
.	O
</s>
<s>
After	O
that	O
,	O
DN	B-Application
was	O
rewritten	O
using	O
Turbo	B-Application
Vision	I-Application
by	O
Stefan	O
Tanurkov	O
and	O
Dmitry	O
Dotsenko	O
(	O
Dotsenko	O
developed	O
DN	B-Application
at	O
Moscow	O
State	O
University	O
)	O
.	O
</s>
<s>
These	O
versions	O
are	O
sometimes	O
referred	O
as	O
DN	B-Application
II	O
.	O
</s>
<s>
In	O
1993	O
,	O
Slava	O
Filimonov	O
invited	O
Stefan	O
to	O
join	O
him	O
to	O
continue	O
producing	O
and	O
publishing	O
DN	B-Application
with	O
joint	O
efforts	O
.	O
</s>
<s>
DN	B-Application
II	O
was	O
actively	O
developed	O
until	O
the	O
start	O
of	O
1995	O
,	O
until	O
version	O
1.35	O
.	O
</s>
<s>
After	O
they	O
left	O
,	O
DN	B-Application
was	O
maintained	O
again	O
by	O
Tanurkov	O
and	O
Maxim	O
Masiutin	O
.	O
</s>
<s>
In	O
1998	O
,	O
the	O
development	O
mostly	O
took	O
a	O
bug-fixing	O
direction	O
as	O
Ritlabs	O
 '	O
product	O
The	B-Application
Bat	I-Application
!	I-Application
</s>
<s>
In	O
late	O
1999	O
,	O
Ritlabs	O
decided	O
to	O
make	O
version	O
1.51	O
of	O
the	O
DOS	B-Application
Navigator	I-Application
completely	O
free	O
with	O
freely	O
available	O
source	O
code	O
.	O
</s>
<s>
Several	O
open	O
source	O
DN	B-Application
branches	O
currently	O
exist	O
including	O
win32/dpmi/os2	O
version	O
"	O
dn/2	O
"	O
and	O
Linux	B-Application
port	O
attempt	O
"	O
dn2l	O
"	O
.	O
</s>
<s>
The	O
original	O
DN	B-Application
contains	O
a	O
large	O
amount	O
of	O
assembler	B-Application
code	O
,	O
complicating	O
ports	O
to	O
other	O
platforms	O
.	O
</s>
<s>
The	O
cross-platform	O
version	O
,	O
DN	B-Application
OSP	O
,	O
in	O
turn	O
,	O
is	O
tied	O
to	O
the	O
Virtual	B-Application
Pascal	I-Application
compiler	O
and	O
runtime	O
library	O
,	O
which	O
are	O
no	O
longer	O
supported	O
.	O
</s>
<s>
No	O
version	O
of	O
DN	B-Application
as	O
of	O
January	O
2022	O
supports	O
Unicode	O
on	O
platforms	O
other	O
than	O
Windows	B-Application
,	O
although	O
cross-platform	O
implementation	O
of	O
Turbo	B-Application
Vision	I-Application
for	O
Pascal	O
with	O
Unicode	O
support	O
exists	O
.	O
</s>
<s>
DN	B-Application
source	O
code	O
was	O
published	O
under	O
the	O
3-clause	O
BSD	B-Operating_System
license	I-Operating_System
.	O
</s>
<s>
However	O
,	O
the	O
code	O
included	O
an	O
implementation	O
of	O
the	O
Turbo	B-Application
Vision	I-Application
library	O
based	O
on	O
the	O
version	O
from	O
the	O
Turbo	B-Application
Pascal	I-Application
distribution	O
,	O
and	O
the	O
latter	O
was	O
never	O
released	O
under	O
a	O
license	O
that	O
allows	O
creation	O
of	O
derivative	O
works	O
.	O
</s>
<s>
In	O
addition	O
,	O
DN	B-Application
OSP	O
contains	O
modified	O
parts	O
of	O
the	O
Virtual	B-Application
Pascal	I-Application
runtime	O
library	O
,	O
while	O
the	O
license	O
for	O
Virtual	B-Application
Pascal	I-Application
itself	O
prohibits	O
distribution	O
of	O
modified	O
versions	O
,	O
however	O
,	O
it	O
is	O
not	O
clear	O
whether	O
this	O
applies	O
only	O
to	O
the	O
compiler	O
or	O
to	O
the	O
runtime	O
library	O
too	O
.	O
</s>
<s>
Other	O
groups	O
release	O
software	O
based	O
on	O
the	O
DN	B-Application
open	O
source	O
code	O
,	O
including	O
features	O
such	O
as	O
support	O
for	O
long	O
filenames	B-Device
,	O
and	O
support	O
for	O
Linux	B-Application
.	O
</s>
