<s>
Dasher	B-Language
is	O
an	O
input	B-General_Concept
method	I-General_Concept
and	O
computer	O
accessibility	O
tool	O
which	O
enables	O
users	O
to	O
compose	O
text	O
without	O
using	O
a	O
keyboard	B-Device
,	O
by	O
entering	O
text	O
on	O
a	O
screen	O
with	O
a	O
pointing	B-Device
device	I-Device
such	O
as	O
a	O
mouse	B-Device
,	O
touch	B-Device
screen	I-Device
,	O
or	O
mice	O
operated	O
by	O
the	O
foot	O
or	O
head	O
.	O
</s>
<s>
Such	O
instruments	O
could	O
serve	O
as	O
prosthetic	O
devices	O
for	O
disabled	O
people	O
who	O
cannot	O
use	O
standard	O
keyboards	B-Device
,	O
or	O
where	O
the	O
use	O
of	O
one	O
is	O
impractical	O
.	O
</s>
<s>
Dasher	B-Language
is	O
free	B-License
and	I-License
open-source	I-License
software	I-License
,	O
subject	O
to	O
the	O
requirements	O
of	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
(	O
GPL	B-License
)	O
,	O
version	O
2	O
.	O
</s>
<s>
Dasher	B-Language
is	O
available	O
for	O
operating	O
systems	O
with	O
GTK+	B-Application
support	O
,	O
i.e.	O
</s>
<s>
Linux	B-Application
,	O
BSDs	B-Operating_System
and	O
other	O
Unix-like	B-Operating_System
including	O
macOS	B-Application
,	O
Microsoft	B-Application
Windows	I-Application
,	O
Pocket	B-Device
PC	I-Device
,	O
iOS	B-Application
and	O
Android	B-Application
.	O
</s>
<s>
Dasher	B-Language
was	O
invented	O
by	O
David	O
J	O
.	O
C	B-Language
.	O
MacKay	O
and	O
developed	O
by	O
David	O
Ward	O
and	O
other	O
members	O
of	O
MacKay	O
's	O
Cambridge	O
research	O
group	O
.	O
</s>
<s>
The	O
Dasher	B-Language
project	O
is	O
supported	O
by	O
the	O
Gatsby	O
Charitable	O
Foundation	O
and	O
by	O
the	O
EU	O
aegis-project	O
.	O
</s>
<s>
For	O
whatever	O
the	O
writer	O
intends	O
to	O
write	O
,	O
they	O
select	O
a	O
letter	O
from	O
ones	O
displayed	O
on	O
a	O
screen	O
by	O
using	O
a	O
pointer	O
,	O
whereupon	O
the	O
system	O
uses	O
a	O
probabilistic	O
predictive	O
model	O
to	O
anticipate	B-Algorithm
the	O
likely	O
character	O
combinations	O
for	O
the	O
next	O
piece	O
of	O
text	O
,	O
and	O
accord	O
these	O
higher	O
priority	O
by	O
displaying	O
them	O
more	O
prominently	O
than	O
less	O
likely	O
letter	O
combinations	O
.	O
</s>
<s>
The	O
Dasher	B-Language
package	O
contains	O
various	O
architecture-independent	O
data	O
files	O
:	O
</s>
