<s>
Genera	B-Application
is	O
a	O
commercial	B-Application
operating	B-General_Concept
system	I-General_Concept
and	O
integrated	B-Application
development	I-Application
environment	I-Application
for	O
Lisp	B-Operating_System
machines	I-Operating_System
created	O
by	O
Symbolics	O
.	O
</s>
<s>
It	O
is	O
essentially	O
a	O
fork	B-Application
of	O
an	O
earlier	O
operating	B-General_Concept
system	I-General_Concept
originating	O
on	O
the	O
Massachusetts	O
Institute	O
of	O
Technology	O
(	O
MIT	O
)	O
AI	B-Application
Lab	O
's	O
Lisp	B-Operating_System
machines	I-Operating_System
which	O
Symbolics	O
had	O
used	O
in	O
common	O
with	O
Lisp	B-Operating_System
Machines	I-Operating_System
,	O
Inc	O
.	O
(	O
LMI	O
)	O
,	O
and	O
Texas	O
Instruments	O
(	O
TI	O
)	O
.	O
</s>
<s>
Genera	B-Application
was	O
also	O
sold	O
by	O
Symbolics	O
as	O
Open	B-Application
Genera	I-Application
,	O
which	O
runs	O
Genera	B-Application
on	O
computers	O
based	O
on	O
a	O
Digital	O
Equipment	O
Corporation	O
(	O
DEC	O
)	O
Alpha	B-Device
processor	I-Device
using	O
Tru64	B-Operating_System
UNIX	I-Operating_System
.	O
</s>
<s>
In	O
2021	O
a	O
new	O
version	O
was	O
released	O
as	O
Portable	O
Genera	B-Application
which	O
runs	O
on	O
DEC	B-Device
Alpha	I-Device
Tru64	B-Operating_System
UNIX	I-Operating_System
,	O
x86_64	O
and	O
Arm64	B-Architecture
Linux	B-Application
,	O
x86_64	O
and	O
Apple	B-Device
M1	I-Device
macOS	B-Application
.	O
</s>
<s>
It	O
is	O
released	O
and	O
licensed	B-License
as	O
proprietary	B-Application
software	I-Application
.	O
</s>
<s>
Genera	B-Application
is	O
an	O
example	O
of	O
an	O
object-oriented	B-Application
operating	I-Application
system	I-Application
based	O
on	O
the	O
programming	O
language	O
Lisp	B-Language
.	O
</s>
<s>
Genera	B-Application
supports	O
incremental	O
and	O
interactive	O
development	O
of	O
complex	O
software	O
using	O
a	O
mix	O
of	O
programming	O
styles	O
with	O
extensive	O
support	O
for	O
object-oriented	B-Language
programming	I-Language
.	O
</s>
<s>
The	O
Lisp	B-Operating_System
Machine	I-Operating_System
operating	B-General_Concept
system	I-General_Concept
was	O
written	O
in	O
Lisp	B-Language
Machine	I-Language
Lisp	I-Language
.	O
</s>
<s>
It	O
was	O
a	O
one-user	O
workstation	O
initially	O
targeted	O
at	O
software	O
developers	O
for	O
artificial	B-Application
intelligence	I-Application
(	O
AI	B-Application
)	O
projects	O
.	O
</s>
<s>
The	O
system	O
had	O
a	O
large	O
bitmap	O
screen	O
,	O
a	O
mouse	O
,	O
a	O
keyboard	O
,	O
a	O
network	B-Architecture
interface	O
,	O
a	O
disk	O
drive	O
,	O
and	O
slots	O
for	O
expansion	O
.	O
</s>
<s>
The	O
operating	B-General_Concept
system	I-General_Concept
was	O
supporting	O
this	O
hardware	O
and	O
it	O
provided	O
(	O
among	O
others	O
)	O
:	O
</s>
<s>
This	O
was	O
already	O
a	O
complete	O
one-user	O
Lisp-based	O
operating	B-General_Concept
system	I-General_Concept
and	O
development	O
environment	O
.	O
</s>
<s>
The	O
MIT	O
Lisp	B-Operating_System
machine	I-Operating_System
operating	B-General_Concept
system	I-General_Concept
was	O
developed	O
from	O
the	O
middle	O
1970s	O
to	O
the	O
early	O
1980s	O
.	O
</s>
<s>
In	O
2006	O
,	O
the	O
source	O
code	O
for	O
this	O
Lisp	B-Operating_System
machine	I-Operating_System
operating	B-General_Concept
system	I-General_Concept
from	O
MIT	O
was	O
released	O
as	O
free	B-License
and	I-License
open-source	I-License
software	I-License
.	O
</s>
<s>
Symbolics	O
developed	O
new	O
Lisp	B-Operating_System
machines	I-Operating_System
and	O
published	O
the	O
operating	B-General_Concept
system	I-General_Concept
under	O
the	O
name	O
Genera	B-Application
.	O
</s>
<s>
Symbolics	B-Application
Genera	I-Application
was	O
developed	O
in	O
the	O
early	O
1980s	O
and	O
early	O
1990s	O
.	O
</s>
<s>
Symbolics	O
developed	O
Genera	B-Application
based	O
on	O
this	O
foundation	O
of	O
the	O
MIT	O
Lisp	B-Operating_System
machine	I-Operating_System
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
It	O
sells	O
the	O
operating	B-General_Concept
system	I-General_Concept
and	O
layered	O
software	O
.	O
</s>
<s>
Some	O
of	O
the	O
layered	O
software	O
has	O
been	O
integrated	O
into	O
Genera	B-Application
in	O
later	O
releases	O
.	O
</s>
<s>
Symbolics	O
improved	O
the	O
operating	B-General_Concept
system	I-General_Concept
software	O
from	O
the	O
original	O
MIT	O
Lisp	B-Operating_System
machine	I-Operating_System
and	O
expanded	O
it	O
.	O
</s>
<s>
The	O
Genera	B-Application
operating	B-General_Concept
system	I-General_Concept
was	O
only	O
available	O
for	O
Symbolics	O
Lisp	B-Operating_System
machines	I-Operating_System
and	O
the	O
Open	B-Application
Genera	I-Application
virtual	B-Architecture
machine	I-Architecture
.	O
</s>
<s>
Symbolics	B-Application
Genera	I-Application
has	O
many	O
features	O
and	O
supports	O
all	O
the	O
versions	O
of	O
various	O
hardware	O
that	O
Symbolics	O
built	O
over	O
its	O
life	O
.	O
</s>
<s>
Symbolics	B-Application
Genera	I-Application
was	O
published	O
on	O
magnetic	B-Architecture
tape	I-Architecture
and	O
CD-ROM	B-Device
.	O
</s>
<s>
The	O
release	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
also	O
provided	O
most	O
of	O
the	O
source	O
code	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
and	O
its	O
applications	O
.	O
</s>
<s>
The	O
user	O
has	O
free	O
access	O
to	O
all	O
parts	O
of	O
the	O
running	O
operating	B-General_Concept
system	I-General_Concept
and	O
can	O
write	O
changes	O
and	O
extensions	O
.	O
</s>
<s>
The	O
source	O
code	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
is	O
divided	O
into	O
systems	O
.	O
</s>
<s>
Symbolics	O
developed	O
a	O
version	O
named	O
Open	B-Application
Genera	I-Application
,	O
that	O
included	O
a	O
virtual	B-Architecture
machine	I-Architecture
that	O
enabled	O
executing	O
Genera	B-Application
on	O
DEC	B-Device
Alpha	I-Device
based	O
workstations	O
,	O
plus	O
several	O
Genera	B-Application
extensions	O
and	O
applications	O
that	O
were	O
sold	O
separately	O
(	O
like	O
the	O
Symbolics	O
S-Graphics	O
suite	O
)	O
.	O
</s>
<s>
Also	O
,	O
they	O
made	O
a	O
new	O
operating	B-General_Concept
system	I-General_Concept
named	O
Minima	O
for	O
embedded	O
uses	O
,	O
in	O
Common	B-Language
Lisp	I-Language
.	O
</s>
<s>
The	O
latest	O
version	O
is	O
Portable	O
Genera	B-Application
,	O
which	O
has	O
the	O
virtual	B-Architecture
machine	I-Architecture
ported	O
to	O
x86_64	O
,	O
Arm64	B-Architecture
and	O
Apple	B-Device
M1	I-Device
processors	O
-	O
additionally	O
to	O
the	O
DEC	B-Device
Alpha	I-Device
processor	O
.	O
</s>
<s>
The	O
virtual	B-Architecture
machine	I-Architecture
then	O
runs	O
under	O
the	O
Linux	B-Application
and	O
macOS	B-Application
,	O
additionally	O
to	O
Tru64	B-Operating_System
UNIX	I-Operating_System
.	O
</s>
<s>
The	O
original	O
Lisp	B-Operating_System
machine	I-Operating_System
operating	B-General_Concept
system	I-General_Concept
was	O
developed	O
in	O
Lisp	B-Language
Machine	I-Language
Lisp	I-Language
,	O
using	O
the	O
Flavors	B-Language
object-oriented	B-Language
extension	O
to	O
that	O
Lisp	B-Language
.	O
</s>
<s>
Symbolics	O
provided	O
a	O
successor	O
to	O
Flavors	B-Language
named	O
New	B-Language
Flavors	I-Language
.	O
</s>
<s>
Later	O
Symbolics	O
also	O
supported	O
Common	B-Language
Lisp	I-Language
and	O
the	O
Common	B-Application
Lisp	I-Application
Object	I-Application
System	I-Application
(	O
CLOS	B-Application
)	O
.	O
</s>
<s>
Then	O
Symbolics	O
Common	B-Language
Lisp	I-Language
became	O
the	O
default	O
Lisp	B-Language
dialect	O
for	O
writing	O
software	O
with	O
Genera	B-Application
.	O
</s>
<s>
The	O
software	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
was	O
written	O
mostly	O
in	O
Lisp	B-Language
Machine	I-Language
Lisp	I-Language
(	O
named	O
ZetaLisp	B-Language
)	O
and	O
Symbolics	O
Common	B-Language
Lisp	I-Language
.	O
</s>
<s>
These	O
Lisp	B-Language
dialects	O
are	O
both	O
provided	O
by	O
Genera	B-Application
.	O
</s>
<s>
Also	O
parts	O
of	O
the	O
software	O
was	O
using	O
either	O
Flavors	B-Language
,	O
New	B-Language
Flavors	I-Language
,	O
and	O
Common	B-Application
Lisp	I-Application
Object	I-Application
System	I-Application
.	O
</s>
<s>
Some	O
of	O
the	O
older	O
parts	O
of	O
the	O
Genera	B-Application
operating	B-General_Concept
system	I-General_Concept
have	O
been	O
rewritten	O
in	O
Symbolics	O
Common	B-Language
Lisp	I-Language
and	O
the	O
Common	B-Application
Lisp	I-Application
Object	I-Application
system	I-Application
.	O
</s>
<s>
Many	O
parts	O
of	O
the	O
operating	B-General_Concept
systems	I-General_Concept
remained	O
written	O
in	O
ZetaLisp	B-Language
and	O
Flavors	B-Language
(	O
or	O
New	B-Language
Flavors	I-Language
)	O
.	O
</s>
<s>
The	O
early	O
versions	O
of	O
Symbolics	B-Application
Genera	I-Application
were	O
built	O
with	O
the	O
original	O
graphical	B-Application
user	I-Application
interface	I-Application
(	O
GUI	B-Application
)	O
windowing	B-Application
system	I-Application
of	O
the	O
Lisp	B-Operating_System
machine	I-Operating_System
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
Symbolics	O
then	O
developed	O
a	O
radically	O
new	O
windowing	B-Application
system	I-Application
named	O
Dynamic	O
Windows	O
with	O
a	O
presentation-based	O
user	B-Application
interface	I-Application
.	O
</s>
<s>
This	O
window	B-Application
system	I-Application
was	O
introduced	O
with	O
Genera	B-Application
7	O
in	O
1986	O
.	O
</s>
<s>
Many	O
of	O
the	O
applications	O
of	O
Genera	B-Application
have	O
then	O
been	O
using	O
Dynamic	O
Windows	O
for	O
their	O
user	B-Application
interface	I-Application
.	O
</s>
<s>
Eventually	O
there	O
was	O
a	O
move	O
to	O
port	O
parts	O
of	O
the	O
window	B-Application
system	I-Application
to	O
run	O
on	O
other	O
Common	B-Language
Lisp	I-Language
implementations	O
by	O
other	O
vendors	O
as	O
the	O
Common	B-Language
Lisp	I-Language
Interface	I-Language
Manager	I-Language
(	O
CLIM	B-Language
)	O
.	O
</s>
<s>
Versions	O
of	O
CLIM	B-Language
have	O
been	O
available	O
(	O
among	O
others	O
)	O
for	O
Allegro	B-Language
Common	I-Language
Lisp	I-Language
,	O
LispWorks	B-Language
,	O
and	O
Macintosh	B-Language
Common	I-Language
Lisp	I-Language
.	O
</s>
<s>
An	O
open	O
source	O
version	O
is	O
available	O
(	O
McCLIM	B-Language
)	O
.	O
</s>
<s>
At	O
runtime	O
the	O
applicable	O
operations	O
to	O
these	O
objects	O
are	O
computed	O
based	O
on	O
the	O
class	O
hierarchy	O
and	O
the	O
available	O
operations	O
(	O
commands	B-Language
)	O
.	O
</s>
<s>
Commands	B-Language
are	O
organized	O
in	O
hierarchical	O
command	O
tables	O
with	O
typed	O
parameters	O
.	O
</s>
<s>
Commands	B-Language
can	O
be	O
entered	O
with	O
the	O
mouse	O
(	O
making	O
extensive	O
use	O
of	O
mouse	O
chording	O
)	O
,	O
keystrokes	O
,	O
and	O
with	O
a	O
command	O
line	O
interface	O
.	O
</s>
<s>
The	O
graphical	O
abilities	O
of	O
the	O
window	B-Application
system	I-Application
are	O
based	O
on	O
the	O
PostScript	B-Language
graphics	O
model	O
.	O
</s>
<s>
The	O
user	B-Application
interface	I-Application
is	O
mostly	O
in	O
monochrome	O
(	O
black	B-Application
and	I-Application
white	I-Application
)	O
since	O
that	O
was	O
what	O
the	O
hardware	O
console	O
typically	O
provided	O
.	O
</s>
<s>
But	O
extensive	O
support	O
exists	O
for	O
color	O
,	O
using	O
color	O
frame	O
buffers	O
or	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
(	O
X11	B-Operating_System
)	O
servers	O
with	O
color	O
support	O
.	O
</s>
<s>
Genera	B-Application
provides	O
a	O
system	O
menu	O
to	O
control	O
windows	O
,	O
switch	O
applications	O
,	O
and	O
operate	O
the	O
window	B-Application
system	I-Application
.	O
</s>
<s>
Many	O
features	O
of	O
the	O
user	B-Application
interface	I-Application
(	O
switching	O
between	O
activities	O
,	O
creating	O
activities	O
,	O
stopping	O
and	O
starting	O
processes	O
,	O
and	O
much	O
more	O
)	O
can	O
also	O
be	O
controlled	O
with	O
keyboard	O
commands	B-Language
.	O
</s>
<s>
The	O
Dynamic	O
Lisp	B-Language
Listener	O
is	O
an	O
example	O
of	O
a	O
command	O
line	O
interface	O
with	O
full	O
graphics	O
abilities	O
and	O
support	O
for	O
mouse-based	O
interaction	O
.	O
</s>
<s>
It	O
accepts	O
Lisp	B-Language
expressions	O
and	O
commands	B-Language
as	O
input	O
.	O
</s>
<s>
The	O
Lisp	B-Language
listener	O
can	O
display	O
forms	O
to	O
input	O
data	O
for	O
the	O
various	O
built-in	O
commands	B-Language
.	O
</s>
<s>
The	O
user	B-Application
interface	I-Application
provides	O
extensive	O
online	B-Protocol
help	I-Protocol
and	O
context	B-Protocol
sensitive	I-Protocol
help	I-Protocol
,	O
completion	O
of	O
choices	O
in	O
various	O
contexts	O
.	O
</s>
<s>
Genera	B-Application
supports	O
fully	O
hyperlinked	O
online	O
documentation	O
.	O
</s>
<s>
The	O
documentation	O
is	O
read	O
with	O
the	O
Document	B-General_Concept
Examiner	I-General_Concept
,	O
an	O
early	O
hypertext	O
browser	O
.	O
</s>
<s>
The	O
documentation	O
is	O
based	O
on	O
small	O
reusable	O
documentation	O
records	O
that	O
can	O
also	O
be	O
displayed	O
in	O
various	O
contexts	O
with	O
the	O
Editor	O
and	O
the	O
Lisp	B-Language
Listener	O
.	O
</s>
<s>
The	O
documentation	O
database	O
information	O
is	O
delivered	O
with	O
Genera	B-Application
and	O
can	O
be	O
modified	O
with	O
incremental	O
patches	O
.	O
</s>
<s>
The	O
documentation	O
was	O
created	O
with	O
a	O
separate	O
application	O
that	O
was	O
not	O
shipped	O
with	O
Genera	B-Application
:	O
Symbolics	O
Concordia	O
.	O
</s>
<s>
Concordia	O
provides	O
an	O
extension	O
to	O
the	O
Zmacs	B-Operating_System
editor	O
for	O
editing	O
documentation	O
records	O
,	O
a	O
graphics	O
editor	O
and	O
a	O
page	O
previewer	O
.	O
</s>
<s>
The	O
documentation	O
provides	O
user	O
guides	O
,	O
installation	O
guidelines	O
and	O
references	O
of	O
the	O
various	O
Lisp	B-Language
constructs	O
and	O
libraries	O
.	O
</s>
<s>
The	O
markup	O
language	O
is	O
based	O
on	O
the	O
Scribe	B-Protocol
markup	I-Protocol
language	I-Protocol
and	O
also	O
usable	O
by	O
the	O
developer	O
.	O
</s>
<s>
Genera	B-Application
supports	O
printing	O
to	O
postscript	B-Language
printers	O
,	O
provides	O
a	O
printing	O
queue	O
and	O
also	O
a	O
PostScript	B-Language
interpreter	O
(	O
written	O
in	O
Lisp	B-Language
)	O
.	O
</s>
<s>
Genera	B-Application
also	O
has	O
support	O
for	O
various	O
network	B-Architecture
protocols	O
and	O
applications	O
using	O
those	O
.	O
</s>
<s>
It	O
has	O
extensive	O
support	O
for	O
TCP/IP	B-Protocol
.	O
</s>
<s>
Genera	B-Application
supports	O
one-processor	O
machines	O
with	O
several	O
threads	O
(	O
called	O
processes	O
)	O
.	O
</s>
<s>
Genera	B-Application
supports	O
several	O
different	O
types	O
of	O
garbage	B-General_Concept
collection	I-General_Concept
(	O
GC	O
)	O
:	O
full	O
GC	O
,	O
in-place	O
GC	O
,	O
incremental	O
GC	O
,	O
and	O
ephemeral	O
GC	O
.	O
</s>
<s>
The	O
ephemeral	O
collector	O
uses	O
only	O
physical	O
memory	O
and	O
uses	O
the	O
memory	B-General_Concept
management	I-General_Concept
unit	O
to	O
get	O
information	O
about	O
changed	O
pages	O
in	O
physical	O
memory	O
.	O
</s>
<s>
The	O
collector	O
uses	O
generations	O
and	O
the	O
virtual	B-Architecture
memory	I-Architecture
is	O
divided	O
into	O
areas	O
.	O
</s>
<s>
Areas	O
can	O
contain	O
objects	O
of	O
certain	O
types	O
(	O
strings	O
,	O
bitmaps	O
,	O
pathnames	O
,	O
...	O
)	O
,	O
and	O
each	O
area	O
can	O
use	O
different	O
memory	B-General_Concept
management	I-General_Concept
mechanisms	O
.	O
</s>
<s>
Genera	B-Application
implements	O
two	O
file	B-Application
systems	I-Application
:	O
the	O
FEP	O
file	B-Application
system	I-Application
for	O
large	O
files	O
and	O
the	O
Lisp	B-Operating_System
Machine	I-Operating_System
File	B-Application
System	I-Application
(	O
LMFS	O
)	O
optimized	O
for	O
many	O
small	O
files	O
.	O
</s>
<s>
If	O
a	O
file	O
is	O
modified	O
,	O
Genera	B-Application
still	O
keeps	O
the	O
old	O
versions	O
.	O
</s>
<s>
Genera	B-Application
also	O
provides	O
access	O
to	O
,	O
can	O
read	O
from	O
and	O
write	O
to	O
,	O
other	O
,	O
local	O
and	O
remote	O
,	O
file	B-Application
systems	I-Application
including	O
:	O
NFS	O
,	O
FTP	O
,	O
HFS	O
,	O
CD-ROMs	B-Device
,	O
tape	O
drives	O
.	O
</s>
<s>
Genera	B-Application
supports	O
netbooting	O
.	O
</s>
<s>
Genera	B-Application
provides	O
a	O
client	O
for	O
the	O
Statice	O
object	B-Application
database	I-Application
from	O
Symbolics	O
.	O
</s>
<s>
Genera	B-Application
makes	O
extensive	O
use	O
of	O
the	O
condition	O
system	O
(	O
exception	O
handling	O
)	O
to	O
handle	O
all	O
kinds	O
of	O
runtime	O
errors	O
and	O
is	O
able	O
to	O
recover	O
from	O
many	O
of	O
these	O
errors	O
.	O
</s>
<s>
For	O
example	O
,	O
it	O
allows	O
retrying	O
network	B-Architecture
operations	O
if	O
a	O
network	B-Architecture
connection	O
has	O
a	O
failure	O
;	O
the	O
application	O
code	O
will	O
keep	O
running	O
.	O
</s>
<s>
Genera	B-Application
has	O
extensive	O
debugging	B-Application
tools	I-Application
.	O
</s>
<s>
Genera	B-Application
can	O
save	O
versions	O
of	O
the	O
running	O
system	O
to	O
worlds	O
.	O
</s>
<s>
Symbolics	O
provided	O
several	O
programming	O
languages	O
for	O
use	O
with	O
Genera	B-Application
:	O
</s>
<s>
Symbolics	O
Common	B-Language
Lisp	I-Language
provides	O
most	O
of	O
the	O
Common	B-Language
Lisp	I-Language
standard	O
with	O
very	O
many	O
extensions	O
,	O
many	O
of	O
them	O
coming	O
from	O
ZetaLisp	B-Language
.	O
</s>
<s>
It	O
is	O
remarkable	O
that	O
these	O
programming	O
language	O
implementations	O
inherited	O
some	O
of	O
the	O
dynamic	O
features	O
of	O
the	O
Lisp	B-Language
system	O
(	O
like	O
garbage	B-General_Concept
collection	I-General_Concept
and	O
checked	O
access	O
to	O
data	O
)	O
and	O
supported	O
incremental	O
software	O
development	O
.	O
</s>
<s>
Third-party	O
developers	O
provided	O
more	O
programming	O
languages	O
,	O
such	O
as	O
OPS5	B-Language
,	O
and	O
development	O
tools	O
,	O
such	O
as	O
the	O
Knowledge	O
Engineering	O
Environment	O
(	O
KEE	O
)	O
from	O
IntelliCorp	O
)	O
.	O
</s>
<s>
Symbolics	B-Application
Genera	I-Application
comes	O
with	O
several	O
applications	O
.	O
</s>
<s>
Peek	O
to	O
examine	O
system	O
information	O
(	O
processes	O
,	O
windows	O
,	O
network	B-Architecture
connections	O
,	O
...	O
)	O
</s>
<s>
Namespace	O
Editor	O
to	O
access	O
information	O
about	O
objects	O
in	O
the	O
network	B-Architecture
(	O
users	O
,	O
computers	O
,	O
file	B-Application
systems	I-Application
,	O
...	O
)	O
</s>
<s>
Symbolics	O
sold	O
several	O
applications	O
that	O
run	O
on	O
Symbolics	B-Application
Genera	I-Application
.	O
</s>
<s>
Several	O
companies	O
developed	O
and	O
sold	O
applications	O
for	O
Symbolics	B-Application
Genera	I-Application
.	O
</s>
<s>
Genera	B-Application
is	O
written	O
fully	O
in	O
Lisp	B-Language
,	O
using	O
ZetaLisp	B-Language
and	O
Symbolics	O
Common	B-Language
Lisp	I-Language
,	O
including	O
all	O
low-level	O
system	O
code	O
,	O
such	O
as	O
device	O
drivers	O
,	O
garbage	B-General_Concept
collection	I-General_Concept
,	O
process	O
scheduler	O
,	O
network	B-Architecture
stacks	O
,	O
etc	O
.	O
</s>
<s>
The	O
source	O
code	O
is	O
more	O
than	O
a	O
million	O
lines	O
of	O
Lisp	B-Language
,	O
yet	O
relatively	O
compact	O
,	O
compared	O
to	O
the	O
provided	O
functions	O
,	O
due	O
to	O
extensive	O
reuse	O
.	O
</s>
<s>
There	O
is	O
little	O
protection	O
against	O
changing	O
the	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
Genera	B-Application
's	O
limits	O
include	O
:	O
</s>
<s>
Only	O
runs	O
on	O
Symbolics	O
Lisp	B-Operating_System
Machines	I-Operating_System
or	O
the	O
Open	B-Application
Genera	I-Application
emulator	O
.	O
</s>
<s>
Only	O
one	O
Lisp	B-Language
system	O
can	O
run	O
at	O
once	O
.	O
</s>
<s>
Data	O
and	O
code	O
is	O
shared	O
by	O
applications	O
and	O
the	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
However	O
,	O
multiple	O
instances	O
of	O
Open	B-Application
Genera	I-Application
can	O
run	O
on	O
one	O
DEC	B-Device
Alpha	I-Device
.	O
</s>
<s>
A	O
stable	O
version	O
of	O
Open	B-Application
Genera	I-Application
that	O
can	O
run	O
on	O
x86-64	B-Device
or	O
arm64	B-Architecture
Linux	B-Application
,	O
and	O
Apple	B-Device
M1	I-Device
MacOS	B-Application
has	O
been	O
released	O
.	O
</s>
<s>
A	O
hacked	O
version	O
of	O
Open	B-Application
Genera	I-Application
that	O
can	O
run	O
on	O
x86-64	B-Device
Linux	B-Application
exists	O
.	O
</s>
