<s>
Tgif	B-Application
(	O
pronounced	O
t-g-i-f	O
)	O
is	O
an	O
Xlib-based	O
interactive	O
2-D	O
drawing	O
tool	O
(	O
using	O
vector	O
graphics	O
)	O
under	O
X11	B-Operating_System
on	O
Linux	B-Application
and	O
most	O
UNIX	B-Application
platforms	O
(	O
including	O
Mac	B-Application
OS	I-Application
X	B-Operating_System
and	O
cygwin	B-Language
on	O
Windows	O
)	O
.	O
</s>
<s>
It	O
was	O
developed	O
since	O
1990	O
and	O
is	O
free	B-Application
software	I-Application
released	O
under	O
the	O
QPL	B-Language
license	O
.	O
</s>
<s>
Because	O
Tgif	B-Application
was	O
developed	O
long	O
before	O
a	O
standard	O
way	O
for	O
drawing	O
programs	O
to	O
work	O
,	O
one	O
might	O
find	O
it	O
unfamiliar	O
to	O
use	O
in	O
a	O
number	O
of	O
ways	O
:	O
</s>
<s>
Although	O
Tgif	B-Application
mention	O
point	O
sizes	O
,	O
it	O
uses	O
a	O
unit	O
that	O
is	O
1/128	O
of	O
an	O
inch	O
for	O
point	O
sizes	O
.	O
</s>
<s>
Unlike	O
modern	O
drawing	O
programs	O
,	O
Tgif	B-Application
uses	O
spline	B-Algorithm
curves	I-Algorithm
instead	O
of	O
Bézier	O
curves	O
.	O
</s>
<s>
Also	O
unlike	O
modern	O
drawing	O
programs	O
,	O
Tgif	B-Application
does	O
not	O
allow	O
the	O
user	O
to	O
select	O
a	O
colour	O
from	O
a	O
color	O
wheel	O
or	O
through	O
controls	O
that	O
allow	O
the	O
user	O
to	O
adjust	O
colour	O
values	O
.	O
</s>
<s>
Instead	O
,	O
Tgif	B-Application
provides	O
a	O
list	O
with	O
a	O
short	O
list	O
of	O
colours	O
.	O
</s>
<s>
"	O
square	O
"	O
)	O
CJK	O
fonts	O
and	O
symbols	O
or	O
dingbat	B-Protocol
fonts	I-Protocol
can	O
be	O
used	O
.	O
</s>
<s>
Because	O
Tgif	B-Application
uses	O
Xlib	O
(	O
which	O
predated	O
modern	O
Unicode	O
support	O
)	O
Tgif	B-Application
does	O
not	O
and	O
cannot	O
support	O
Unicode	O
.	O
</s>
<s>
Tgif	B-Application
saves	O
drawings	O
in	O
a	O
Prolog-based	O
plain	O
text	O
file	O
format	O
.	O
</s>
<s>
Because	O
the	O
program	O
is	O
based	O
on	O
Prolog	B-Language
,	O
there	O
is	O
n't	O
a	O
lot	O
of	O
support	O
from	O
other	O
programs	O
for	O
reading	O
the	O
Tgif	B-Application
file	O
format	O
.	O
</s>
<s>
Fonts	O
are	O
represented	O
as	O
PostScript	B-Language
font	O
names	O
.	O
</s>
<s>
Originally	O
,	O
it	O
was	O
possible	O
to	O
print	O
Tgif	B-Application
drawings	O
in	O
batch	B-General_Concept
mode	I-General_Concept
without	O
using	O
an	O
X	B-Operating_System
display	I-Operating_System
.	O
</s>
<s>
Currently	O
,	O
in	O
order	O
to	O
print	O
drawings	O
,	O
the	O
user	O
would	O
need	O
to	O
be	O
running	O
Tgif	B-Application
on	O
an	O
X	B-Operating_System
display	I-Operating_System
.	O
</s>
