<s>
Claws	B-Language
Mail	I-Language
is	O
a	O
free	B-License
and	I-License
open-source	I-License
,	O
C/GTK	O
-based	O
e-mail	B-Protocol
client	I-Protocol
,	O
which	O
is	O
both	O
lightweight	O
and	O
highly	O
configurable	O
.	O
</s>
<s>
Claws	B-Language
Mail	I-Language
runs	O
on	O
both	O
Windows	B-Application
and	O
Unix-like	B-Operating_System
systems	I-Operating_System
such	O
as	O
Linux	B-Application
,	O
BSD	B-Operating_System
,	O
and	O
Solaris	B-Application
.	O
</s>
<s>
It	O
stores	O
mail	O
in	O
the	O
MH	B-Protocol
mailbox	O
format	O
.	O
</s>
<s>
Plugins	B-Application
allow	O
to	O
read	O
HTML	O
mail	O
,	O
but	O
there	O
is	O
none	O
to	O
compose	O
HTML	O
messages	O
.	O
</s>
<s>
Claws	B-Language
Mail	I-Language
is	O
also	O
a	O
News	B-Protocol
client	I-Protocol
and	O
RSS	B-Application
aggregator	I-Application
.	O
</s>
<s>
Further	O
features	O
–	O
integrated	O
or	O
supplied	O
via	O
plugins	B-Application
–	O
include	O
:	O
</s>
<s>
Development	O
started	O
in	O
April	O
2001	O
as	O
Sylpheed-Claws	B-Language
off	O
the	O
development	O
version	O
of	O
Sylpheed	B-Language
,	O
where	O
new	O
features	O
could	O
be	O
tested	O
and	O
debugged	O
.	O
</s>
<s>
In	O
August	O
2005	O
Claws	B-Language
Mail	I-Language
forked	O
completely	O
from	O
Sylpheed	B-Language
.	O
</s>
