<s>
EPOC	B-Language
is	O
a	O
mobile	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
developed	O
by	O
Psion	B-Application
,	O
a	O
British	O
company	O
founded	O
in	O
1980	O
.	O
</s>
<s>
It	O
began	O
as	O
a	O
16-bit	B-Device
operating	B-General_Concept
system	I-General_Concept
(	O
OS	O
)	O
for	O
Psion	B-Application
's	O
own	O
x86-compatible	O
devices	O
,	O
and	O
was	O
later	O
replaced	O
by	O
a	O
32-bit	O
system	O
for	O
x86	B-Operating_System
and	O
ARM	B-Architecture
.	O
</s>
<s>
Psion	B-Application
licensed	O
the	O
32-bit	O
system	O
to	O
other	O
hardware	O
makers	O
,	O
such	O
as	O
Ericsson	O
.	O
</s>
<s>
To	O
distinguish	O
it	O
from	O
the	O
16-bit	B-Device
OS	O
,	O
the	O
32-bit	O
version	O
was	O
sometimes	O
called	O
EPOC32	O
.	O
</s>
<s>
Technologically	O
,	O
it	O
was	O
a	O
major	O
departure	O
from	O
the	O
16-bit	B-Device
version	O
(	O
which	O
came	O
to	O
be	O
called	O
EPOC16	O
or	O
SIBO	O
)	O
.	O
</s>
<s>
In	O
1998	O
,	O
the	O
32-bit	O
version	O
was	O
renamed	O
Symbian	B-Operating_System
OS	I-Operating_System
.	O
</s>
<s>
After	O
Nokia	O
acquired	O
the	O
rights	O
to	O
Symbian	B-Operating_System
in	O
2010	O
,	O
they	O
published	O
Symbian	B-Operating_System
's	O
source	O
code	O
under	O
the	O
Eclipse	B-License
Public	I-License
License	I-License
.	O
</s>
<s>
The	O
name	O
EPOC	B-Language
comes	O
from	O
the	O
word	O
epoch	O
(	O
the	O
beginning	O
of	O
an	O
era	O
)	O
.	O
</s>
<s>
The	O
name	O
was	O
shortened	O
to	O
four	O
letters	O
to	O
accord	O
with	O
the	O
names	O
of	O
such	O
software	O
innovations	O
as	O
Unix	B-Application
and	O
Mach	B-Operating_System
.	O
</s>
<s>
Initially	O
the	O
operating	B-General_Concept
system	I-General_Concept
was	O
capitalised	O
as	O
Epoc	B-Language
rather	O
than	O
'	O
EPOC	B-Language
 '	O
,	O
since	O
it	O
is	O
not	O
an	O
acronym	O
.	O
</s>
<s>
The	O
change	O
to	O
all	O
capital	O
letters	O
was	O
made	O
on	O
the	O
recommendation	O
of	O
Psion	B-Application
's	O
marketing	O
department	O
.	O
</s>
<s>
Thereafter	O
,	O
a	O
rumour	O
circulated	O
in	O
the	O
technical	O
press	O
that	O
EPOC	B-Language
was	O
an	O
acronym	O
for	O
"	O
Electronic	B-Language
Piece	I-Language
of	I-Language
Cheese	I-Language
"	O
.	O
</s>
<s>
When	O
Psion	B-Application
started	O
developing	O
a	O
32-bit	O
operating	B-General_Concept
system	I-General_Concept
in	O
1994	O
,	O
they	O
kept	O
it	O
under	O
the	O
EPOC	B-Language
brand	O
.	O
</s>
<s>
Then	O
it	O
became	O
conventional	O
within	O
the	O
company	O
to	O
refer	O
to	O
EPOC16	O
as	O
SIBO	O
,	O
which	O
was	O
the	O
codename	O
of	O
Psion	B-Application
's	O
16-bit	B-Device
mobile	O
computing	O
initiative	O
.	O
</s>
<s>
This	O
change	O
freed	O
them	O
use	O
the	O
name	O
EPOC	B-Language
for	O
EPOC32	O
.	O
</s>
<s>
In	O
June	O
1998	O
,	O
Psion	B-Application
formed	O
a	O
limited	O
company	O
,	O
named	O
Symbian	B-Operating_System
Ltd.	O
,	O
with	O
the	O
telecommunications	O
corporations	O
Nokia	O
,	O
Ericsson	O
,	O
and	O
Motorola	O
.	O
</s>
<s>
By	O
buying	O
into	O
the	O
new	O
firm	O
,	O
the	O
telecommunications	O
corporations	O
each	O
acquired	O
a	O
stake	O
in	O
Psion	B-Application
's	O
EPOC	B-Language
operating	B-General_Concept
system	I-General_Concept
and	O
other	O
intellectual	O
property	O
.	O
</s>
<s>
Symbian	B-Operating_System
Ltd	O
.	O
changed	O
the	O
name	O
of	O
EPOC/EPOC32	O
to	O
Symbian	B-Operating_System
OS	I-Operating_System
,	O
which	O
debuted	O
in	O
November	O
2000	O
on	O
the	O
Nokia	B-Language
9210	I-Language
Communicator	I-Language
smartphone	B-Application
.	O
</s>
<s>
EPOC	B-Language
was	O
developed	O
at	O
Psion	B-Application
,	O
a	O
software	O
and	O
mobile-device	O
company	O
founded	O
in	O
London	O
in	O
1980	O
.	O
</s>
<s>
The	O
company	O
released	O
its	O
first	O
pocket	B-Device
computer	I-Device
in	O
1984	O
:	O
an	O
8-bit	O
device	O
named	O
the	O
Psion	B-Application
Organiser	I-Application
.	O
</s>
<s>
Psion	B-Application
saw	O
a	O
need	O
to	O
develop	O
a	O
16-bit	B-Device
operating	B-General_Concept
system	I-General_Concept
to	O
drive	O
their	O
next	O
generation	O
of	O
devices	O
.	O
</s>
<s>
First	O
,	O
however	O
,	O
they	O
needed	O
to	O
engineer	O
a	O
16-bit	B-Device
single-board	B-Device
computer	I-Device
,	O
something	O
that	O
was	O
extremely	O
difficult	O
at	O
the	O
time	O
.	O
</s>
<s>
To	O
develop	O
the	O
SIBO	O
hardware	O
and	O
software	O
,	O
they	O
needed	O
samples	O
of	O
the	O
16-bit	B-Device
microprocessors	B-Architecture
they	O
would	O
be	O
programming	O
;	O
but	O
it	O
took	O
more	O
than	O
a	O
year	O
to	O
secure	O
the	O
chips	O
,	O
which	O
caused	O
a	O
significant	O
delay	O
.	O
</s>
<s>
By	O
1987	O
,	O
development	O
of	O
EPOC	B-Language
was	O
underway	O
:	O
It	O
was	O
a	O
single-user	O
,	O
preemptive	O
multitasking	O
operating	B-General_Concept
system	I-General_Concept
designed	O
to	O
run	O
in	O
read-only	B-Device
memory	I-Device
(	O
ROM	B-Device
)	O
.	O
</s>
<s>
The	O
operating	B-General_Concept
system	I-General_Concept
and	O
its	O
programmes	O
were	O
written	O
in	O
Intel	B-General_Concept
8086	I-General_Concept
assembly	B-Language
language	I-Language
and	O
C	B-Language
.	O
When	O
the	O
operating	B-General_Concept
system	I-General_Concept
started	O
,	O
it	O
opened	O
the	O
pre-installed	O
programmes	O
in	O
advance	O
so	O
that	O
the	O
system	O
could	O
switch	O
between	O
them	O
quickly	O
.	O
</s>
<s>
To	O
enable	O
users	O
to	O
write	O
and	O
run	O
their	O
own	O
programmes	O
,	O
EPOC	B-Language
featured	O
an	O
updated	O
version	O
of	O
the	O
Open	B-Language
Programming	I-Language
Language	I-Language
(	O
OPL	O
)	O
,	O
which	O
was	O
first	O
published	O
with	O
the	O
Psion	B-Application
Organiser	I-Application
.	O
</s>
<s>
OPL	O
was	O
a	O
simple	O
interpreted	B-Application
language	I-Application
somewhat	O
like	O
BASIC	O
.	O
</s>
<s>
In	O
1989	O
,	O
Psion	B-Application
released	O
the	O
first	O
16-bit	B-Device
computers	I-Device
to	O
be	O
equipped	O
with	O
the	O
new	O
operating	B-General_Concept
system	I-General_Concept
:	O
the	O
MC200	O
and	O
MC400	O
notebooks	B-Device
.	O
</s>
<s>
Each	O
of	O
these	O
had	O
an	O
Intel	B-General_Concept
80C86	I-General_Concept
processor	O
,	O
but	O
differed	O
in	O
some	O
other	O
specifications	O
,	O
such	O
as	O
memory	O
capacity	O
.	O
</s>
<s>
Among	O
the	O
later	O
SIBO	O
devices	O
were	O
the	O
Psion	B-Application
Series	I-Application
3	I-Application
(	O
1991	O
)	O
,	O
3A	O
(	O
1993	O
)	O
,	O
3C	O
(	O
1996	O
)	O
,	O
Workabout	O
series	O
,	O
and	O
the	O
Siena	O
512K	O
model	O
(	O
1996	O
)	O
.	O
</s>
<s>
The	O
final	O
EPOC	B-Language
device	O
was	O
the	O
Psion	B-Application
Series	I-Application
3mx	I-Application
(	O
1998	O
)	O
.	O
</s>
<s>
The	O
user	B-Application
interface	I-Application
differed	O
by	O
device	O
.	O
</s>
<s>
The	O
notebook	B-Device
computers	I-Device
had	O
a	O
windows	O
,	O
icons	O
,	O
menus	O
,	O
pointer	O
(	O
WIMP	B-Application
)	O
graphical	B-Application
user	I-Application
interface	I-Application
(	O
GUI	B-Application
)	O
.	O
</s>
<s>
The	O
handheld	O
computers	O
,	O
which	O
had	O
smaller	O
screens	O
and	O
no	O
pointing	B-Device
device	I-Device
,	O
accept	O
input	O
from	O
a	O
keyboard	O
or	O
a	O
stylus	B-Device
.	O
</s>
<s>
In	O
parallel	O
with	O
the	O
production	O
of	O
their	O
16-bit	B-Device
devices	O
,	O
Psion	B-Application
had	O
been	O
developing	O
a	O
32-bit	O
version	O
of	O
EPOC	B-Language
since	O
late	O
1994	O
.	O
</s>
<s>
The	O
move	O
to	O
32	O
bits	O
was	O
necessary	O
to	O
remain	O
competitive	O
,	O
and	O
Psion	B-Application
wanted	O
to	O
have	O
a	O
mobile	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
they	O
could	O
license	O
to	O
other	O
companies	O
.	O
</s>
<s>
For	O
the	O
32-bit	O
operating	B-General_Concept
system	I-General_Concept
,	O
the	O
engineers	O
wrote	O
a	O
new	O
object-oriented	B-Language
codebase	B-General_Concept
in	O
C++	B-Language
.	O
</s>
<s>
Where	O
EPOC16	O
was	O
designed	O
specifically	O
for	O
the	O
Intel	B-Device
80186	I-Device
platform	O
,	O
EPOC32	O
was	O
built	O
for	O
ARM	B-Architecture
,	O
a	O
computing	B-Device
platform	I-Device
called	O
a	O
reduced	B-Architecture
instruction	I-Architecture
set	I-Architecture
computer	I-Architecture
(	O
RISC	B-Architecture
)	O
,	O
which	O
instruction	B-General_Concept
set	I-General_Concept
architecture	I-General_Concept
is	O
smaller	O
and	O
of	O
more	O
uniform	O
length	O
than	O
in	O
an	O
alternative	O
complex	B-Architecture
instruction	I-Architecture
set	I-Architecture
computer	I-Architecture
(	O
CISC	O
)	O
.	O
</s>
<s>
Like	O
EPOC16	O
,	O
EPOC32	O
was	O
a	O
single-user	O
,	O
pre-emptive	O
multitasking	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
It	O
also	O
featured	O
memory	B-General_Concept
protection	I-General_Concept
,	O
which	O
was	O
an	O
essential	O
feature	O
for	O
modern	O
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
Psion	B-Application
licensed	O
EPOC32	O
to	O
other	O
device	O
manufacturers	O
,	O
and	O
made	O
it	O
possible	O
for	O
manufacturers	O
to	O
change	O
or	O
replace	O
the	O
system	O
's	O
GUI	B-Application
.	O
</s>
<s>
Because	O
of	O
the	O
licensing	O
arrangement	O
,	O
Psion	B-Application
considered	O
spinning-off	O
their	O
software	O
division	O
as	O
Psion	B-Application
Software	O
.	O
</s>
<s>
Psion	B-Application
's	O
own	O
PDAs	B-Application
had	O
a	O
GUI	B-Application
named	O
Eikon	O
.	O
</s>
<s>
Visually	O
,	O
Eikon	O
was	O
a	O
refinement	O
of	O
design	O
choices	O
from	O
Psion	B-Application
's	O
8	O
-	O
and	O
16-bit	B-Device
devices	O
.	O
</s>
<s>
The	O
first	O
published	O
version	O
,	O
called	O
Release	O
1	O
,	O
appeared	O
on	O
the	O
Psion	B-Application
Series	I-Application
5	I-Application
ROM	B-Device
v1.0	O
in	O
June	O
1997	O
.	O
</s>
<s>
Release	O
2	O
was	O
never	O
published	O
,	O
but	O
an	O
updated	O
ROM	B-Device
(	O
version	O
1.1	O
)	O
for	O
the	O
Series	O
5	O
featured	O
Release	O
3	O
.	O
</s>
<s>
The	O
Series	O
5	O
used	O
Psion	B-Application
's	O
new	O
user	B-Application
interface	I-Application
,	O
Eikon	O
.	O
</s>
<s>
One	O
of	O
the	O
first	O
EPOC	B-Language
licensees	O
was	O
a	O
short-lived	O
company	O
named	O
Geofox	O
;	O
they	O
halted	O
production	O
after	O
selling	O
fewer	O
than	O
1,000	O
units	O
.	O
</s>
<s>
Another	O
licensee	O
,	O
Oregon	O
Scientific	O
,	O
released	O
a	O
budget	O
device	O
named	O
Osaris	B-Application
;	O
it	O
was	O
the	O
only	O
EPOC	B-Language
device	O
to	O
ship	O
with	O
Release	O
4	O
.	O
</s>
<s>
EPOC	B-Language
Release	O
5	O
premiered	O
in	O
March	O
1999	O
.	O
</s>
<s>
It	O
ran	O
on	O
ARMv4	O
processors	O
,	O
such	O
as	O
the	O
StrongARM	B-Device
series	O
.	O
</s>
<s>
In	O
addition	O
to	O
its	O
email	O
,	O
messaging	O
,	O
and	O
data	O
synchronisation	O
features	O
,	O
it	O
introduced	O
support	O
for	O
the	O
Java	B-Language
Development	I-Language
Kit	I-Language
,	O
which	O
made	O
it	O
capable	O
of	O
running	O
a	O
wider	O
variety	O
of	O
programmes	O
.	O
</s>
<s>
In	O
2000	O
,	O
EPOC	B-Language
's	O
GUI	B-Application
variations	O
were	O
replaced	O
with	O
three	O
reference	O
interfaces	O
:	O
Crystal	O
was	O
for	O
devices	O
with	O
a	O
small	O
keyboard	O
;	O
Quartz	O
was	O
for	O
"	O
communicator	O
"	O
devices	O
(	O
which	O
had	O
some	O
telecommunication	O
features	O
,	O
and	O
tended	O
to	O
be	O
equipped	O
with	O
a	O
thumb	B-Device
keyboard	I-Device
)	O
;	O
and	O
Pearl	O
was	O
for	O
mobile	O
phones	O
.	O
</s>
<s>
Each	O
classification	O
supported	O
VGA	B-Protocol
graphics	I-Protocol
.	O
</s>
<s>
Psion	B-Application
deployed	O
Release	O
5	O
on	O
their	O
5mx	B-Application
series	I-Application
(	O
1999	O
)	O
,	O
Revo	B-Application
(	O
1999	O
)	O
,	O
netBook	B-Application
(	O
1999	O
)	O
,	O
Series	B-Application
7	I-Application
(	O
1999	O
)	O
,	O
Revo	B-Application
Plus	O
(	O
2000	O
)	O
,	O
and	O
netPad	O
(	O
2001	O
)	O
devices	O
.	O
</s>
<s>
Ericsson	O
rebranded	O
the	O
Psion	B-Application
Series	I-Application
5mx	I-Application
as	O
the	O
MC218	B-Application
,	O
and	O
SONICblue	O
rebranded	O
the	O
Revo	B-Application
as	O
the	O
Diamond	B-Application
Mako	I-Application
;	O
like	O
the	O
original	O
devices	O
,	O
the	O
rebranded	O
versions	O
were	O
released	O
in	O
1999	O
.	O
</s>
<s>
The	O
Ericsson	B-Language
R380	I-Language
smartphone	B-Application
,	O
released	O
in	O
November	O
2000	O
,	O
was	O
the	O
first	O
device	O
to	O
be	O
distributed	O
with	O
EPOC	B-Language
Release	O
5.1	O
.	O
</s>
<s>
Psion	B-Application
developed	O
an	O
ER5u-enabled	O
device	O
codenamed	O
"	O
Conan	O
"	O
,	O
but	O
it	O
did	O
not	O
advance	O
beyond	O
the	O
prototype	O
stage	O
.	O
</s>
<s>
The	O
device	O
was	O
intended	O
to	O
be	O
a	O
Bluetooth-enabled	O
successor	O
to	O
the	O
Revo	B-Application
.	O
</s>
<s>
In	O
June	O
1998	O
,	O
Psion	B-Application
Software	O
became	O
Symbian	B-Operating_System
Ltd.	O
,	O
a	O
major	O
joint	O
venture	O
between	O
Psion	B-Application
and	O
phone	O
manufacturers	O
Ericsson	O
,	O
Motorola	O
,	O
and	O
Nokia	O
.	O
</s>
<s>
The	O
next	O
release	O
of	O
EPOC32	O
,	O
Release	O
6	O
,	O
was	O
rebranded	O
Symbian	B-Operating_System
OS	I-Operating_System
.	O
</s>
<s>
It	O
decoupled	O
the	O
user	B-Application
interface	I-Application
from	O
the	O
underlying	O
operating	B-General_Concept
system	I-General_Concept
,	O
which	O
afforded	O
device	O
manufacturers	O
the	O
ability	O
(	O
or	O
burden	O
)	O
of	O
implementing	O
a	O
graphical	B-Application
interface	I-Application
on	O
their	O
devices	O
.	O
</s>
<s>
The	O
final	O
version	O
of	O
Symbian	B-Operating_System
OS	I-Operating_System
to	O
be	O
released	O
was	O
v10.1	O
;	O
the	O
final	O
update	O
was	O
published	O
in	O
2012	O
.	O
</s>
