<s>
Oberon	B-Application
is	O
a	O
general-purpose	O
programming	O
language	O
first	O
published	O
in	O
1987	O
by	O
Niklaus	O
Wirth	O
and	O
the	O
latest	O
member	O
of	O
the	O
Wirthian	O
family	O
of	O
ALGOL-like	B-Language
languages	O
(	O
Euler	B-Language
,	O
ALGOL	B-Language
W	I-Language
,	O
Pascal	B-Application
,	O
Modula	B-Language
,	O
and	O
Modula-2	B-Language
)	O
.	O
</s>
<s>
Oberon	B-Application
was	O
the	O
result	O
of	O
a	O
concentrated	O
effort	O
to	O
increase	O
the	O
power	O
of	O
Modula-2	B-Language
,	O
the	O
direct	O
successor	O
of	O
Pascal	B-Application
,	O
and	O
simultaneously	O
to	O
reduce	O
its	O
complexity	O
.	O
</s>
<s>
Oberon	B-Application
was	O
developed	O
as	O
part	O
of	O
the	O
implementation	O
of	O
an	O
operating	B-General_Concept
system	I-General_Concept
,	O
also	O
named	O
Oberon	B-Application
at	O
ETH	O
Zurich	O
in	O
Switzerland	B-Protocol
.	O
</s>
<s>
The	O
name	O
is	O
from	O
the	O
moon	O
of	O
the	O
planet	O
Uranus	O
,	O
named	O
Oberon	B-Application
.	O
</s>
<s>
Oberon	B-Application
is	O
still	O
maintained	O
by	O
Wirth	O
and	O
the	O
latest	O
Project	B-Application
Oberon	I-Application
compiler	O
update	O
is	O
dated	O
6	O
March	O
2020	O
.	O
</s>
<s>
Oberon	B-Application
is	O
designed	O
with	O
a	O
motto	O
attributed	O
to	O
Albert	O
Einstein	O
in	O
mind	O
:	O
“	O
Make	O
things	O
as	O
simple	O
as	O
possible	O
,	O
but	O
not	O
simpler.	O
”	O
The	O
principal	O
guideline	O
was	O
to	O
concentrate	O
on	O
features	O
that	O
are	O
basic	O
and	O
essential	O
and	O
to	O
omit	O
ephemeral	O
issues	O
.	O
</s>
<s>
Another	O
factor	O
was	O
recognition	O
of	O
the	O
growth	O
of	O
complexity	O
in	O
languages	O
such	O
as	O
C++	B-Language
and	O
Ada	B-Language
.	O
</s>
<s>
In	O
contrast	O
to	O
these	O
,	O
Oberon	B-Application
emphasizes	O
the	O
use	O
of	O
the	O
library	B-Library
concept	O
to	O
extend	O
the	O
language	O
.	O
</s>
<s>
Enumeration	O
and	O
subrange	O
types	O
,	O
which	O
were	O
present	O
in	O
Modula-2	B-Language
,	O
were	O
omitted	O
,	O
and	O
set	O
types	O
are	O
limited	O
to	O
sets	O
of	O
integers	O
.	O
</s>
<s>
All	O
imported	O
items	O
must	O
be	O
qualified	O
by	O
the	O
name	O
of	O
the	O
module	B-Architecture
where	O
they	O
are	O
declared	O
.	O
</s>
<s>
Low-level	O
facilities	O
are	O
highlighted	O
by	O
only	O
allowing	O
them	O
to	O
be	O
used	O
in	O
a	O
module	B-Architecture
which	O
includes	O
the	O
identifier	O
SYSTEM	O
in	O
its	O
import	O
list	O
.	O
</s>
<s>
Strict	O
type	O
checking	O
,	O
even	O
across	O
modules	B-Architecture
,	O
and	O
index	O
checking	O
at	B-Library
runtime	I-Library
,	O
null	O
pointer	O
checking	O
,	O
and	O
the	O
safe	O
type	O
extension	O
concept	O
largely	O
allow	O
programming	O
to	O
rely	O
on	O
the	O
language	O
rules	O
alone	O
.	O
</s>
<s>
Oberon	B-Application
compilers	O
have	O
been	O
viewed	O
as	O
compact	O
and	O
fast	O
,	O
while	O
providing	O
code	O
quality	O
comparable	O
to	O
commercial	O
compilers	O
.	O
</s>
<s>
Features	O
characterizing	O
the	O
Oberon	B-Application
language	O
include	O
:	O
</s>
<s>
Oberon	B-Application
supports	O
extension	O
of	O
record	O
types	O
for	O
the	O
construction	O
of	O
abstractions	O
and	O
heterogeneous	O
structures	O
.	O
</s>
<s>
In	O
contrast	O
to	O
the	O
later	O
dialects	O
,	O
Oberon-2	B-Language
and	O
Active	B-Language
Oberon	I-Language
,	O
the	O
original	O
Oberon	B-Application
lacks	O
a	O
dispatch	O
mechanism	O
as	O
a	O
language	O
feature	O
but	O
has	O
it	O
as	O
a	O
programming	O
technique	O
or	O
design	O
pattern	O
.	O
</s>
<s>
In	O
the	O
Oberon	B-Application
operating	I-Application
system	I-Application
,	O
two	O
programming	O
techniques	O
are	O
used	O
together	O
for	O
the	O
dispatch	O
call	O
:	O
Method	O
suite	O
and	O
Message	O
handler	O
.	O
</s>
<s>
In	O
this	O
technique	O
,	O
a	O
table	O
of	O
procedure	O
variables	O
is	O
defined	O
and	O
a	O
global	O
variable	O
of	O
this	O
type	O
is	O
declared	O
in	O
the	O
extended	O
module	B-Architecture
and	O
assigned	O
back	O
in	O
the	O
generic	O
module	B-Architecture
:	O
</s>
<s>
MODULE	B-Architecture
Rectangles	O
;	O
</s>
<s>
Dynamic	O
dispatch	O
is	O
only	O
done	O
via	O
procedures	O
in	O
Figures	O
module	B-Architecture
that	O
is	O
the	O
generic	O
module	B-Architecture
.	O
</s>
<s>
MODULE	B-Architecture
Rectangles	O
;	O
</s>
<s>
In	O
the	O
Oberon	B-Application
operating	I-Application
system	I-Application
both	O
of	O
these	O
techniques	O
are	O
used	O
for	O
dynamic	O
dispatch	O
.	O
</s>
<s>
The	O
first	O
one	O
is	O
used	O
for	O
a	O
known	O
set	O
of	O
methods	O
;	O
the	O
second	O
is	O
used	O
for	O
any	O
new	O
methods	O
declared	O
in	O
the	O
extension	O
module	B-Architecture
.	O
</s>
<s>
For	O
example	O
,	O
if	O
the	O
extension	O
module	B-Architecture
Rectangles	O
were	O
to	O
implement	O
a	O
new	O
Rotate( )	O
procedure	O
,	O
within	O
the	O
Figures	O
module	B-Architecture
it	O
could	O
only	O
be	O
called	O
via	O
a	O
message	O
handler	O
.	O
</s>
<s>
No-cost	O
implementations	O
of	O
Oberon	B-Application
(	O
the	O
language	O
)	O
and	O
Oberon	B-Application
(	O
the	O
operating	B-General_Concept
system	I-General_Concept
)	O
can	O
be	O
found	O
on	O
the	O
Internet	O
(	O
several	O
are	O
from	O
ETHZ	O
itself	O
)	O
.	O
</s>
<s>
For	O
example	O
,	O
object-oriented	B-Language
programming	I-Language
(	O
OOP	O
)	O
features	O
were	O
added	O
,	O
the	O
FOR	O
loop	O
was	O
reinstated	O
.	O
</s>
<s>
The	O
result	O
was	O
Oberon-2	B-Language
.	O
</s>
<s>
One	O
release	O
,	O
named	O
Native	O
Oberon	B-Application
which	O
includes	O
an	O
operating	B-General_Concept
system	I-General_Concept
,	O
and	O
can	O
directly	O
boot	O
on	O
IBM	O
PC	O
compatible	O
class	O
hardware	O
.	O
</s>
<s>
A	O
.NET	B-Application
implementation	O
of	O
Oberon	B-Application
with	O
the	O
addition	O
of	O
some	O
minor	O
.NET-related	O
extensions	O
was	O
also	O
developed	O
at	O
ETHZ	O
.	O
</s>
<s>
In	O
1993	O
,	O
an	O
ETHZ	O
spin	O
off	O
company	O
brought	O
a	O
dialect	O
of	O
Oberon-2	B-Language
to	O
the	O
market	O
named	O
Oberon-L	O
.	O
</s>
<s>
In	O
1997	O
,	O
it	O
was	O
renamed	O
Component	B-Language
Pascal	I-Language
.	O
</s>
<s>
Oberon-2	B-Language
compilers	O
developed	O
by	O
ETH	O
include	O
versions	O
for	O
Microsoft	B-Application
Windows	I-Application
,	O
Linux	B-Application
,	O
Solaris	B-Application
,	O
and	O
classic	B-Application
Mac	I-Application
OS	I-Application
.	O
</s>
<s>
Implementations	O
from	O
other	O
sources	O
exist	O
for	O
some	O
other	O
operating	B-General_Concept
systems	I-General_Concept
,	O
including	O
Atari	B-Application
TOS	I-Application
and	O
AmigaOS	B-Application
.	O
</s>
<s>
There	O
is	O
an	O
Oberon-2	B-Language
Lex	B-General_Concept
scanner	O
and	O
Yacc	B-Application
parser	B-Language
by	O
Stephen	O
J	O
Bevan	O
of	O
Manchester	O
University	O
,	O
UK	O
,	O
based	O
on	O
the	O
one	O
in	O
the	O
Mössenböck	O
and	O
Wirth	O
reference	O
.	O
</s>
<s>
Other	O
compilers	O
include	O
Oxford	O
Oberon-2	B-Language
,	O
which	O
also	O
understands	O
Oberon-07	O
,	O
and	O
Vishap	O
Oberon	B-Application
.	O
</s>
<s>
The	O
latter	O
is	O
based	O
on	O
Josef	O
Templ	O
's	O
Oberon	B-Application
to	O
C	B-Language
language	I-Language
source-to-source	B-Language
compiler	I-Language
(	O
transpiler	B-Language
)	O
named	O
Ofront	O
,	O
which	O
in	O
turn	O
is	O
based	O
on	O
the	O
OP2	O
Compiler	O
developed	O
by	O
Regis	O
Crelier	O
at	O
ETHZ	O
.	O
</s>
<s>
Oberon-07	O
,	O
defined	O
by	O
Niklaus	O
Wirth	O
in	O
2007	O
and	O
revised	O
in	O
2008	O
,	O
2011	O
,	O
2013	O
,	O
2014	O
,	O
2015	O
,	O
and	O
2016	O
is	O
based	O
on	O
the	O
original	O
version	O
of	O
Oberon	B-Application
rather	O
than	O
Oberon-2	B-Language
.	O
</s>
<s>
The	O
main	O
changes	O
are	O
:	O
explicit	O
numeric	O
conversion	O
functions	O
(	O
e.g.	O
,	O
FLOOR	O
and	O
FLT	O
)	O
must	O
be	O
used	O
,	O
the	O
WITH	O
,	O
LOOP	O
and	O
EXIT	O
statements	O
were	O
omitted	O
,	O
WHILE	O
statements	O
were	O
extended	O
,	O
CASE	O
statements	O
can	O
be	O
used	O
for	O
type	O
extension	O
tests	O
,	O
RETURN	O
statements	O
can	O
only	O
be	O
connected	O
to	O
the	O
end	O
of	O
a	O
function	O
,	O
imported	O
variables	O
and	O
structured	B-Language
value	O
parameters	O
are	O
read-only	O
and	O
arrays	O
can	O
be	O
assigned	O
without	O
using	O
COPY	O
.	O
</s>
<s>
Oberon-07	O
compilers	O
have	O
been	O
developed	O
for	O
use	O
with	O
many	O
different	O
computer	O
systems	O
.	O
</s>
<s>
Wirth	O
's	O
compiler	O
targets	O
a	O
reduced	B-Architecture
instruction	I-Architecture
set	I-Architecture
computer	I-Architecture
(	O
RISC	B-Architecture
)	O
processor	O
of	O
his	O
own	O
design	O
that	O
was	O
used	O
to	O
implement	O
the	O
2013	O
version	O
of	O
the	O
Project	B-Application
Oberon	I-Application
operating	B-General_Concept
system	I-General_Concept
on	O
a	O
Xilinx	O
field-programmable	B-Architecture
gate	I-Architecture
array	I-Architecture
(	O
FPGA	B-Architecture
)	O
Spartan-3	O
board	O
.	O
</s>
<s>
Ports	O
of	O
the	O
RISC	B-Architecture
processor	I-Architecture
to	O
FPGA	B-Architecture
Spartan-6	O
,	O
Spartan-7	O
,	O
Artix-7	O
and	O
a	O
RISC	B-Architecture
emulator	O
for	O
Windows	B-Application
(	O
compilable	O
on	O
Linux	B-Application
and	O
macOS	B-Application
,	O
and	O
binaries	O
available	O
for	O
Windows	B-Application
)	O
also	O
exist	O
.	O
</s>
<s>
compiles	O
via	O
C	B-Language
and	O
can	O
be	O
used	O
on	O
any	O
Portable	O
Operating	B-General_Concept
System	I-General_Concept
Interface	O
(	O
POSIX	O
)	O
compatible	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
The	O
commercial	O
implementation	O
targets	O
32-bit	O
ARM	B-Architecture
Cortex-M3	O
,	O
M4	O
and	O
M7	O
microcontrollers	O
.	O
</s>
<s>
The	O
compiler	O
produces	O
64-bit	O
Windows	B-Application
binaries	O
.	O
</s>
<s>
produces	O
32-bit	B-Application
Windows	I-Application
binaries	O
and	O
implements	O
revision	O
2008	O
of	O
the	O
language	O
.	O
</s>
<s>
produces	O
binaries	O
for	O
both	O
Windows	B-Application
and	O
Linux	B-Application
.	O
</s>
<s>
translates	O
Oberon	B-Application
to	O
JavaScript	B-Language
.	O
</s>
<s>
is	O
an	O
implementation	O
for	O
the	O
Java	B-Language
virtual	I-Language
machine	I-Language
.	O
</s>
<s>
Active	B-Language
Oberon	I-Language
is	O
yet	O
another	O
variant	O
of	O
Oberon	B-Application
,	O
which	O
adds	O
objects	O
(	O
with	O
object-centered	O
access	O
protection	O
and	O
local	O
activity	O
control	O
)	O
,	O
system-guarded	O
assertions	O
,	O
preemptive	O
priority	O
scheduling	O
and	O
a	O
changed	O
syntax	O
for	O
methods	O
(	O
named	O
type-bound	O
procedures	O
in	O
Oberon	B-Application
vocabulary	O
)	O
.	O
</s>
<s>
Further	O
,	O
Active	B-Language
Oberon	I-Language
has	O
a	O
way	O
to	O
implement	O
operators	O
(	O
including	O
overloading	O
)	O
,	O
an	O
advanced	O
syntax	O
for	O
using	O
arrays	O
(	O
see	O
and	O
Proceedings	O
of	O
the	O
7th	O
Joint	O
Modular	B-Architecture
Languages	O
Conference	O
2006	O
Oxford	O
,	O
UK	O
)	O
,	O
and	O
knows	O
about	O
namespaces	O
.	O
</s>
<s>
The	O
operating	B-General_Concept
system	I-General_Concept
A2	B-Application
(	O
formerly	O
Active	O
Object	B-Language
System	I-Language
(	O
AOS	O
)	O
,	O
then	O
Bluebottle	O
)	O
,	O
especially	O
the	O
kernel	B-Operating_System
,	O
synchronizes	O
and	O
coordinates	O
different	O
active	O
objects	O
.	O
</s>
<s>
ETHZ	O
has	O
released	O
Active	B-Language
Oberon	I-Language
which	O
supports	O
active	O
objects	O
,	O
and	O
the	O
operating	B-General_Concept
systems	I-General_Concept
based	O
thereon	O
(	O
Active	O
Object	B-Language
System	I-Language
(	O
AOS	O
)	O
,	O
Bluebottle	O
,	O
A2	B-Application
)	O
,	O
and	O
environment	O
(	O
JDK	O
,	O
HTTP	O
,	O
FTP	O
,	O
etc	O
.	O
)	O
</s>
<s>
As	O
of	O
2003	O
,	O
supported	O
central	B-General_Concept
processing	I-General_Concept
units	I-General_Concept
(	O
CPUs	O
)	O
include	O
single	O
and	O
dual	O
core	O
x86	B-Operating_System
,	O
and	O
StrongARM	B-Device
.	O
</s>
<s>
A	O
further	O
extension	O
of	O
Oberon-2	B-Language
was	O
originally	O
named	O
Oberon/L	O
but	O
later	O
renamed	O
to	O
Component	B-Language
Pascal	I-Language
(	O
CP	O
)	O
.	O
</s>
<s>
CP	O
was	O
developed	O
for	O
Windows	B-Application
and	O
classic	B-Application
Mac	I-Application
OS	I-Application
by	O
Oberon	B-Application
microsystems	O
,	O
a	O
commercial	O
spin-off	O
company	O
from	O
ETHZ	O
,	O
and	O
for	O
.NET	B-Application
by	O
Queensland	O
University	O
of	O
Technology	O
.	O
</s>
<s>
Further	O
,	O
the	O
languages	O
Lagoona	O
and	O
Obliq	B-Language
carry	O
Oberon	B-Application
methods	O
into	O
specialized	O
areas	O
.	O
</s>
<s>
Later	O
.NET	B-Application
development	O
efforts	O
at	O
ETHZ	O
focused	O
on	O
a	O
new	O
language	O
named	O
Zonnon	B-Language
.	O
</s>
<s>
This	O
includes	O
the	O
features	O
of	O
Oberon	B-Application
and	O
restores	O
some	O
from	O
Pascal	B-Application
(	O
enumerated	O
types	O
,	O
built-in	O
IO	O
)	O
but	O
has	O
some	O
syntactic	O
differences	O
.	O
</s>
<s>
Oberon-V	B-Language
(	O
originally	O
named	O
Seneca	B-Language
,	O
after	O
Seneca	B-Language
the	O
Younger	O
)	O
is	O
a	O
descendant	O
of	O
Oberon	B-Application
designed	O
for	O
numerical	O
applications	O
on	O
supercomputers	B-Architecture
,	O
especially	O
vector	O
or	O
pipelined	B-General_Concept
architectures	O
.	O
</s>
