<s>
Psi	B-Language
is	O
a	O
free	B-Application
instant	B-Application
messaging	I-Application
client	B-Protocol
for	O
the	O
XMPP	B-Protocol
protocol	I-Protocol
(	O
including	O
such	O
services	O
as	O
Google	B-Application
Talk	I-Application
)	O
which	O
uses	O
the	O
Qt	B-Language
toolkit	I-Language
.	O
</s>
<s>
It	O
runs	O
on	O
Linux	B-Application
(	O
and	O
other	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
)	O
,	O
Windows	B-Application
,	O
macOS	B-Operating_System
and	O
OS/2	B-Application
(	O
including	O
eComStation	B-Device
and	O
ArcaOS	B-Device
)	O
.	O
</s>
<s>
For	O
example	O
,	O
there	O
are	O
"	O
multi	O
windows	B-Application
"	O
and	O
"	O
all	O
in	O
one	O
"	O
modes	O
,	O
support	O
of	O
different	O
iconsets	O
and	O
themes	O
.	O
</s>
<s>
Ready-to-install	O
deb	O
and	O
RPM	B-Application
packages	I-Application
are	O
available	O
for	O
many	O
Linux	B-Application
distributions	I-Application
.	O
</s>
<s>
Successful	O
ports	O
of	O
Psi	B-Language
were	O
reported	O
for	O
Haiku	B-Language
,	O
FreeBSD	B-Operating_System
and	O
Sun	B-Application
Solaris	I-Application
operating	O
systems	O
.	O
</s>
<s>
Due	O
to	O
Psi	B-Language
's	O
free/open	O
-source	O
nature	O
,	O
several	O
forks	B-Application
have	O
appeared	O
,	O
which	O
occasionally	O
contain	O
features	O
that	O
may	O
appear	O
in	O
future	O
official	O
Psi	B-Language
versions	O
.	O
</s>
<s>
'	O
Psi	B-Language
 '	O
is	O
the	O
twenty-third	O
letter	O
of	O
the	O
Greek	O
alphabet	O
( Ψ	O
)	O
,	O
which	O
is	O
used	O
as	O
the	O
software	O
's	O
logo	O
.	O
</s>
<s>
The	O
goal	O
of	O
the	O
Psi	B-Language
project	O
is	O
to	O
create	O
a	O
powerful	O
,	O
yet	O
easy-to-use	O
XMPP	B-Protocol
client	B-Protocol
that	O
tries	O
to	O
strictly	O
adhere	O
to	O
the	O
XMPP	B-Protocol
drafts	O
and	O
XMPP	B-Protocol
XEPs	O
.	O
</s>
<s>
This	O
means	O
that	O
in	O
most	O
cases	O
,	O
Psi	B-Language
will	O
not	O
implement	O
a	O
feature	O
unless	O
there	O
is	O
an	O
accepted	O
standard	O
for	O
it	O
in	O
the	O
XMPP	B-Protocol
community	O
.	O
</s>
<s>
Doing	O
so	O
ensures	O
that	O
Psi	B-Language
will	O
be	O
compatible	O
,	O
stable	O
,	O
and	O
predictable	O
.	O
</s>
<s>
At	O
various	O
points	O
during	O
its	O
existence	O
Karneges	O
was	O
paid	O
to	O
develop	O
the	O
codebase	O
,	O
during	O
which	O
Psi	B-Language
flourished	O
.	O
</s>
<s>
Typically	O
however	O
,	O
the	O
release	O
cycle	O
of	O
Psi	B-Language
is	O
relatively	O
slow	O
,	O
but	O
the	O
client	B-Protocol
has	O
always	O
been	O
seen	O
by	O
its	O
fans	O
as	O
a	O
very	O
stable	O
and	O
powerful	O
instant	B-Application
messaging	I-Application
client	B-Protocol
.	O
</s>
<s>
In	O
2002	O
Michail	O
Pishchagin	O
started	O
hacking	O
Qt	B-Language
code	O
which	O
later	O
became	O
libpsi	O
library	O
.	O
</s>
<s>
Pishchagin	O
joined	O
the	O
team	O
in	O
March	O
2003	O
and	O
he	O
is	O
responsible	O
for	O
many	O
large	O
chunks	O
in	O
Psi	B-Language
code	O
.	O
</s>
<s>
In	O
2009	O
,	O
Smith	O
handed	O
maintenance	O
back	O
to	O
Karneges	O
,	O
who	O
also	O
maintains	O
Iris	O
,	O
the	O
Qt/C	O
++	O
XMPP	B-Protocol
library	O
upon	O
which	O
Psi	B-Language
is	O
based	O
.	O
</s>
<s>
Remko	O
Tronçon	O
started	O
writing	O
his	O
custom	O
patches	O
for	O
Psi	B-Language
in	O
2003	O
,	O
and	O
became	O
an	O
official	O
developer	O
in	O
May	O
2005	O
.	O
</s>
<s>
In	O
2009	O
a	O
Psi	B-Language
fork	B-Application
named	O
was	O
started	O
.	O
</s>
<s>
As	O
of	O
2017	O
all	O
active	O
Psi+	O
developers	O
have	O
become	O
official	O
Psi	B-Language
developers	O
,	O
and	O
now	O
Psi+	O
is	O
just	O
a	O
development	O
branch	O
of	O
Psi	B-Language
with	O
rolling	O
release	O
development	O
model	O
.	O
</s>
<s>
Users	O
who	O
wants	O
to	O
receive	O
new	O
features	O
and	O
bug	O
fixes	O
very	O
quickly	O
may	O
use	O
Psi+	O
on	O
daily	O
basis	O
.	O
</s>
<s>
Users	O
who	O
do	O
not	O
care	O
about	O
new	O
trends	O
and	O
prefer	O
constancy	O
may	O
choose	O
Psi	B-Language
as	O
it	O
uses	O
classical	O
development	O
model	O
and	O
its	O
releases	O
are	O
quite	O
rare	O
.	O
</s>
<s>
Because	O
XMPP	B-Protocol
allows	O
gateways	O
to	O
other	O
services	O
,	O
which	O
many	O
servers	O
support	O
,	O
it	O
can	O
also	O
connect	O
to	O
Yahoo	O
!,	O
AIM	B-Protocol
,	O
Gadu-Gadu	B-Application
,	O
ICQ	B-Protocol
and	O
Microsoft	O
networks	O
.	O
</s>
<s>
Other	O
services	O
available	O
using	O
gateway	O
servers	O
include	O
RSS	O
and	O
Atom	B-Application
news	O
feeds	O
,	O
sending	O
SMS	O
messages	O
to	O
cellular	O
networks	O
and	O
weather	O
reports	O
.	O
</s>
<s>
As	O
of	O
2012	O
,	O
Psi	B-Language
has	O
language	O
packs	O
for	O
20	O
languages	O
,	O
with	O
more	O
being	O
created	O
.	O
</s>
<s>
Emoticon	B-Protocol
packs	O
are	O
supported	O
using	O
the	O
jisp	O
format	O
.	O
</s>
<s>
Many	O
jisp	O
emoticon	B-Protocol
packs	O
are	O
available	O
,	O
including	O
ones	O
from	O
AIM	B-Protocol
,	O
iChat	B-Protocol
,	O
and	O
Trillian	B-Protocol
.	O
</s>
<s>
Psi	B-Language
supports	O
file	O
transfers	O
between	O
other	O
XMPP	B-Protocol
clients	O
,	O
and	O
it	O
is	O
possible	O
to	O
send	O
to	O
or	O
receive	O
files	O
from	O
other	O
IM	B-Application
networks	O
,	O
if	O
the	O
user	O
's	O
servers	O
support	O
this	O
.	O
</s>
<s>
Psi	B-Language
supports	O
Contact	O
Is	O
Typing	O
Notification	O
(	O
which	O
works	O
with	O
Yahoo	O
!,	O
MSN	O
,	O
and	O
AIM	B-Protocol
contacts	O
)	O
.	O
</s>
<s>
Version	O
0.10	O
,	O
released	O
in	O
January	O
2006	O
,	O
brought	O
automatically	O
resizing	O
contact	O
list	O
and	O
composing	O
window	O
in	O
chat	O
dialogs	O
,	O
tabbed	O
chats	O
,	O
support	O
for	O
Growl	O
messaging	O
system	O
on	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
,	O
window	O
transparency	O
and	O
many	O
other	O
changes	O
.	O
</s>
<s>
Support	O
of	O
audio	O
and	O
video	O
calls	O
in	O
Psi	B-Language
via	O
Jingle	O
is	O
implemented	O
via	O
officially	O
supported	O
plugin	O
PsiMedia	O
.	O
</s>
<s>
Security	O
is	O
also	O
a	O
major	O
consideration	O
,	O
and	O
Psi	B-Language
provides	O
it	O
for	O
both	O
client-to-server	O
(	O
TLS	O
)	O
and	O
client-to-client	O
(	O
OpenPGP	O
,	O
OTR	B-Protocol
,	O
and	O
OMEMO	B-Application
)	O
via	O
appropriate	O
plugins	O
.	O
</s>
<s>
Encryption	O
of	O
messages	O
in	O
group	O
chats	O
is	O
supported	O
only	O
via	O
OMEMO	B-Application
plugin	O
.	O
</s>
