<s>
Project	B-Operating_System
Builder	I-Operating_System
was	O
an	O
integrated	B-Application
development	I-Application
environment	I-Application
(	O
IDE	O
)	O
originally	O
developed	O
by	O
NeXT	O
for	O
version	O
3	O
of	O
the	O
NeXTSTEP	B-Application
operating	B-General_Concept
system	I-General_Concept
by	O
separating	O
out	O
the	O
code	O
editing	O
parts	O
of	O
Interface	O
Builder	O
into	O
its	O
own	O
application	O
.	O
</s>
<s>
After	O
Apple	O
Computer	O
purchased	O
NeXT	O
and	O
turned	O
NeXTSTEP	B-Application
into	O
the	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
operating	B-General_Concept
system	I-General_Concept
,	O
the	O
NeXTSTEP	B-Application
version	O
of	O
Project	B-Operating_System
Builder	I-Operating_System
became	O
ProjectBuilderWO	O
(	O
maintained	O
only	O
for	O
WebObjects	B-Language
development	O
)	O
,	O
and	O
they	O
created	O
a	O
new	O
Project	B-Operating_System
Builder	I-Operating_System
from	O
scratch	O
for	O
software	O
development	O
with	O
the	O
first	O
version	O
being	O
introduced	O
with	O
Developer	O
Preview	O
4	O
of	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
.	O
</s>
<s>
This	O
version	O
of	O
Project	B-Operating_System
Builder	I-Operating_System
,	O
informally	O
dubbed	O
PBX	O
.	O
</s>
<s>
was	O
distributed	O
with	O
the	O
first	O
few	O
versions	O
of	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
but	O
with	O
the	O
release	O
of	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
v10.3	I-Operating_System
it	O
was	O
redesigned	O
,	O
reintegrated	O
with	O
Interface	O
Builder	O
and	O
rebranded	O
as	O
Xcode	B-Operating_System
.	O
</s>
<s>
GNUstep	B-Application
's	O
ProjectCenter	O
IDE	O
is	O
a	O
rough	O
workalike	O
of	O
the	O
original	O
NextStep	B-Application
design	O
;	O
additional	O
functionality	O
is	O
provided	O
by	O
ProjectManager	O
,	O
a	O
3rd-party	O
GNUstep	B-Application
IDE	O
meant	O
for	O
greater	O
usability	O
.	O
</s>
