<s>
PVCS	B-Protocol
Version	O
Manager	O
(	O
originally	O
named	O
Polytron	B-Protocol
Version	I-Protocol
Control	I-Protocol
System	I-Protocol
)	O
is	O
a	O
software	O
package	O
by	O
Serena	O
Software	O
Inc.	O
,	O
for	O
version	B-Architecture
control	I-Architecture
of	O
source	O
code	O
files	O
.	O
</s>
<s>
PVCS	B-Protocol
follows	O
the	O
"	O
locking	O
"	O
approach	O
to	O
concurrency	O
control	O
;	O
it	O
has	O
no	O
merge	B-General_Concept
operator	O
built-in	O
(	O
but	O
does	O
,	O
nonetheless	O
,	O
have	O
a	O
separate	O
merge	B-General_Concept
command	O
)	O
.	O
</s>
<s>
However	O
PVCS	B-Protocol
can	O
also	O
be	O
configured	O
to	O
support	O
several	O
users	O
simultaneously	O
attempting	O
to	O
edit	O
the	O
file	O
;	O
in	O
this	O
case	O
the	O
second	O
chronological	O
committer	O
will	O
have	O
a	O
branch	O
created	O
for	O
them	O
so	O
that	O
both	O
modifications	O
,	O
instead	O
of	O
conflicting	O
,	O
will	O
appear	O
as	O
parallel	O
histories	O
for	O
the	O
same	O
file	O
.	O
</s>
<s>
This	O
is	O
unlike	O
Concurrent	B-Application
Versions	I-Application
System	I-Application
(	O
CVS	B-Application
)	O
and	O
Subversion	B-Application
where	O
the	O
second	O
committer	O
needs	O
to	O
first	O
merge	B-General_Concept
the	O
changes	O
via	O
the	O
update	O
command	O
and	O
then	O
resolve	O
conflicts	O
(	O
when	O
they	O
exist	O
)	O
before	O
actually	O
committing	O
.	O
</s>
<s>
Synergex	O
ported	O
both	O
the	O
PVCS	B-Protocol
Version	O
Manager	O
and	O
the	O
PVCS	B-Protocol
Configuration	O
Builder	O
(	O
an	O
extended	O
make	B-Application
utility	I-Application
,	O
including	O
a	O
variant	O
of	O
the	O
command	O
line	O
tool	O
make	O
)	O
to	O
various	O
Unix	B-Application
platforms	O
and	O
OpenVMS	B-Operating_System
.	O
</s>
<s>
In	O
2009	O
,	O
Serena	O
Software	O
clarified	O
that	O
it	O
will	O
continue	O
to	O
invest	O
in	O
PVCS	B-Protocol
and	O
provide	O
support	O
to	O
PVCS	B-Protocol
customers	O
for	O
the	O
foreseeable	O
future.PVCS	O
Version	O
Manager	O
8.5	O
release	O
(	O
2014	O
)	O
introduces	O
both	O
new	O
feature	O
and	O
new	O
platform	O
support	O
.	O
</s>
<s>
In	O
2016	O
,	O
Micro	O
Focus	O
International	O
announced	O
the	O
acquisition	O
of	O
Serena	O
Software	O
to	O
again	O
become	O
the	O
custodians	O
of	O
PVCS	B-Protocol
.	O
</s>
