<s>
Terminal	B-Application
Productivity	I-Application
Executive	I-Application
(	O
TPX	O
)	O
,	O
is	O
a	O
multiple	O
session	O
manager	O
for	O
IBM	B-Device
mainframes	I-Device
.	O
</s>
<s>
It	O
allows	O
connected	O
users	O
to	O
access	O
resources	O
with	O
a	O
single	O
sign-on	O
:	O
It	O
holds	O
several	O
sessions	O
concurrently	O
,	O
allowing	O
a	O
person	O
to	O
switch	O
among	O
them	O
via	O
the	O
single	O
connection	O
on	O
their	O
physical	B-General_Concept
terminal	I-General_Concept
or	O
terminal	B-Application
emulator	I-Application
application	O
,	O
i.e.	O
</s>
<s>
telnet	B-Protocol
.	O
</s>
<s>
For	O
each	O
session	O
,	O
TPX	O
uses	O
a	O
virtual	B-Application
terminal	I-Application
.	O
</s>
<s>
users	O
can	O
use	O
it	O
to	O
switch	O
amongst	O
ISPF	B-Operating_System
and	O
SDSF	B-Application
in	O
the	O
TSO	B-Application
.	O
</s>
<s>
TPX	O
is	O
primarily	O
used	O
on	O
z/OS	B-Application
,	O
but	O
a	O
version	O
also	O
exists	O
for	O
z/VM	B-Application
.	O
</s>
