<s>
The	O
Magic	B-Library
User	I-Library
Interface	I-Library
(	O
MUI	O
in	O
short	O
)	O
is	O
an	O
object-oriented	B-Language
system	O
by	O
Stefan	O
Stuntz	O
to	O
generate	O
and	O
maintain	O
graphical	B-Application
user	I-Application
interfaces	I-Application
.	O
</s>
<s>
The	O
Magic	B-Library
User	I-Library
Interface	I-Library
was	O
written	O
for	O
AmigaOS	B-Application
and	O
gained	O
popularity	O
amongst	O
both	O
programmers	O
and	O
users	O
.	O
</s>
<s>
It	O
has	O
been	O
ported	O
to	O
PowerPC	B-Architecture
processors	I-Architecture
and	O
adopted	O
as	O
the	O
default	O
GUI	B-Library
toolkit	I-Library
of	O
the	O
MorphOS	B-Operating_System
operating	O
system	O
.	O
</s>
<s>
The	O
MUI	O
application	O
programmer	O
interface	O
has	O
been	O
cloned	O
by	O
the	O
Zune	B-Library
toolkit	O
used	O
in	O
the	O
AROS	B-Application
Research	I-Application
Operating	I-Application
System	I-Application
.	O
</s>
<s>
Creating	O
GUI	B-Application
applications	O
on	O
Amiga	B-Device
was	O
difficult	O
for	O
a	O
very	O
long	O
time	O
,	O
mainly	O
because	O
the	O
programmer	O
got	O
only	O
a	O
minuscule	O
amount	O
of	O
support	O
from	O
the	O
operating	O
system	O
.	O
</s>
<s>
Even	O
the	O
preference	O
programs	O
on	O
the	O
Workbench	B-Operating_System
were	O
still	O
only	O
using	O
the	O
default	O
fixed-width	O
font	O
.	O
</s>
<s>
In	O
1992	O
Stefan	O
Stuntz	O
started	O
developing	O
a	O
new	O
object-oriented	B-Language
GUI	B-Library
toolkit	I-Library
for	O
Amiga	B-Device
.	O
</s>
<s>
Main	O
goals	O
for	O
new	O
GUI	B-Library
toolkit	I-Library
were	O
:	O
</s>
<s>
System	O
integration	O
:	O
Every	O
program	O
has	O
an	O
ARexx	B-Operating_System
port	O
and	O
can	O
be	O
iconified	O
or	O
uniconified	O
by	O
pushing	O
a	O
gadget	O
or	O
by	O
using	O
the	O
Commodities	O
exchange	O
program	O
.	O
</s>
<s>
MUI	O
was	O
released	O
as	O
shareware	B-License
.	O
</s>
<s>
Starting	O
from	O
MUI	O
3.9	O
an	O
unrestricted	O
version	O
is	O
integrated	O
with	O
MorphOS	B-Operating_System
,	O
but	O
a	O
shareware	B-License
key	O
is	O
still	O
required	O
to	O
activate	O
all	O
user	O
configuration	O
options	O
in	O
AmigaOS	B-Application
.	O
</s>
<s>
UI	O
development	O
is	O
done	O
at	O
source-code	O
level	O
without	O
the	O
aid	O
of	O
GUI	B-Application
builders	O
.	O
</s>
<s>
In	O
MUI	O
application	O
the	O
programmer	O
only	O
defines	O
logical	O
structure	O
of	O
the	O
GUI	B-Application
and	O
the	O
layout	O
is	O
determined	O
on	O
run	O
time	O
depending	O
on	O
user	O
configuration	O
.	O
</s>
<s>
Unlike	O
on	O
other	O
GUI	B-Library
toolkits	I-Library
developer	O
does	O
not	O
determine	O
exact	O
coordinates	O
for	O
UI	O
objects	O
but	O
only	O
their	O
relative	O
placement	O
to	O
each	O
other	O
using	O
object	O
groups	O
.	O
</s>
<s>
In	O
traditional	O
Intuition-based	O
UI	O
coding	O
programmer	O
had	O
to	O
calculate	O
placement	O
of	O
gadgets	O
relative	O
to	O
font	O
and	O
border	O
sizes	O
.	O
</s>
<s>
It	O
is	O
also	O
possible	O
to	O
embed	O
other	O
BOOPSI	B-Device
based	O
GUI	B-Library
toolkit	I-Library
objects	O
inside	O
a	O
MUI	O
application	O
.	O
</s>
<s>
Some	O
notable	O
applications	O
that	O
use	O
MUI	O
as	O
a	O
widget	B-Library
toolkit	I-Library
include	O
:	O
</s>
<s>
Currently	O
there	O
are	O
two	O
main	O
widget	B-Library
toolkits	I-Library
in	O
the	O
Amiga	B-Device
world	O
,	O
which	O
are	O
competing	O
with	O
each	O
other	O
.	O
</s>
<s>
The	O
most	O
widely	O
used	O
is	O
MUI	O
(	O
adopted	O
into	O
AROS	B-Application
,	O
MorphOS	B-Operating_System
and	O
in	O
most	O
Amiga	B-Device
programs	O
)	O
,	O
the	O
other	O
one	O
is	O
ReAction	B-Library
which	O
was	O
adopted	O
in	O
AmigaOS	B-Application
3.5	O
.	O
</s>
<s>
There	O
is	O
in	O
development	O
a	O
GTK	B-Application
MUI	O
wrapper	O
and	O
it	O
will	O
allow	O
the	O
porting	O
of	O
various	O
GTK	B-Application
based	O
software	O
.	O
</s>
<s>
MUI	O
extended	O
Workbench	B-Operating_System
's	O
four-colour	O
palette	B-Data_Structure
with	O
four	O
additional	O
colours	O
,	O
allowing	O
smoother	O
gradients	O
with	O
less	O
noticeable	O
dithering	O
.	O
</s>
<s>
The	O
MagicWB	B-Operating_System
companion	O
to	O
MUI	O
made	O
use	O
of	O
this	O
extended	O
palette	B-Data_Structure
to	O
provide	O
more	O
attractive	O
icons	O
to	O
replace	O
the	O
dated	O
Workbench	B-Operating_System
defaults	O
.	O
</s>
<s>
MUI	O
4	O
added	O
support	O
for	O
alpha	B-Algorithm
blending	I-Algorithm
and	O
support	O
for	O
user	O
defined	O
widget	O
shapes	O
.	O
</s>
