<s>
tvtwm	B-Device
is	O
an	O
X	B-Application
window	I-Application
manager	I-Application
derived	O
from	O
twm	B-Language
to	O
which	O
it	O
adds	O
the	O
virtual	B-Application
desktop	I-Application
feature	O
from	O
swm	B-Device
.	O
</s>
<s>
All	O
of	O
these	O
window	O
managers	O
were	O
originally	O
written	O
by	O
Tom	B-Language
LaStrange	I-Language
.	O
</s>
<s>
The	O
current	O
maintainer	O
of	O
tvtwm	B-Device
is	O
Chris	O
Ross	O
.	O
</s>
<s>
James	O
Tanis	O
believes	O
he	O
may	O
be	O
the	O
only	O
remaining	O
user	O
of	O
tvtwm	B-Device
,	O
and	O
placed	O
a	O
notice	O
on	O
his	O
web	O
site	O
seeking	O
other	O
users	O
who	O
would	O
like	O
a	O
bug	O
fix	O
release	O
.	O
</s>
<s>
Unlike	O
most	O
more	O
recent	O
virtual	B-Application
window	I-Application
managers	I-Application
,	O
tvtwm	B-Device
models	O
the	O
root	O
window	O
as	O
a	O
single	O
large	O
space	O
,	O
with	O
the	O
physical	O
desktop	O
being	O
a	O
viewport	O
onto	O
that	O
virtual	O
root	O
window	O
.	O
</s>
<s>
The	O
user	O
can	O
scroll	O
the	O
viewport	O
around	O
the	O
virtual	B-Application
desktop	I-Application
either	O
by	O
pressing	O
certain	O
keys	O
or	O
by	O
clicking	O
into	O
a	O
scaled	O
down	O
representation	O
of	O
the	O
virtual	B-Application
desktop	I-Application
,	O
the	O
so-called	O
panner	O
.	O
</s>
