<s>
The	O
Enterprise	B-General_Concept
Objects	I-General_Concept
Framework	I-General_Concept
,	O
or	O
simply	O
EOF	O
,	O
was	O
introduced	O
by	O
NeXT	O
in	O
1994	O
as	O
a	O
pioneering	O
object-relational	B-General_Concept
mapping	I-General_Concept
product	O
for	O
its	O
NeXTSTEP	B-Application
and	O
OpenStep	B-Operating_System
development	O
platforms	O
.	O
</s>
<s>
EOF	O
abstracts	O
the	O
process	O
of	O
interacting	O
with	O
a	O
relational	B-Application
database	I-Application
by	O
mapping	O
database	O
rows	O
to	O
Java	B-Language
or	O
Objective-C	B-Language
objects	O
.	O
</s>
<s>
This	O
largely	O
relieves	O
developers	O
from	O
writing	O
low-level	O
SQL	B-Language
code	O
.	O
</s>
<s>
EOF	O
enjoyed	O
some	O
niche	O
success	O
in	O
the	O
mid-1990s	O
among	O
financial	O
institutions	O
who	O
were	O
attracted	O
to	O
the	O
rapid	O
application	O
development	O
advantages	O
of	O
NeXT	O
's	O
object-oriented	B-Language
platform	O
.	O
</s>
<s>
Since	O
Apple	O
Inc	O
's	O
merger	O
with	O
NeXT	O
in	O
1996	O
,	O
EOF	O
has	O
evolved	O
into	O
a	O
fully	O
integrated	O
part	O
of	O
WebObjects	B-Language
,	O
an	O
application	O
server	O
also	O
originally	O
from	O
NeXT	O
.	O
</s>
<s>
Many	O
of	O
the	O
core	O
concepts	O
of	O
EOF	O
re-emerged	O
as	O
part	O
of	O
Core	B-Application
Data	I-Application
,	O
which	O
further	O
abstracts	O
the	O
underlying	O
data	O
formats	O
to	O
allow	O
it	O
to	O
be	O
based	O
on	O
non-SQL	O
stores	O
.	O
</s>
<s>
Every	O
data	O
source	O
has	O
a	O
different	O
data-access	O
language	O
(	O
or	O
API	B-Application
)	O
,	O
driving	O
up	O
the	O
costs	O
to	O
learn	O
and	O
use	O
each	O
vendor	O
's	O
product	O
.	O
</s>
<s>
The	O
NeXT	O
engineers	O
wanted	O
to	O
apply	O
the	O
advantages	O
of	O
object-oriented	B-Language
programming	I-Language
,	O
by	O
getting	O
objects	O
to	O
"	O
talk	O
"	O
to	O
relational	B-Application
databases	I-Application
.	O
</s>
<s>
As	O
the	O
two	O
technologies	O
are	O
very	O
different	O
,	O
the	O
solution	O
was	O
to	O
create	O
an	O
abstraction	O
layer	O
,	O
insulating	O
developers	O
from	O
writing	O
the	O
low-level	O
procedural	O
code	O
(	O
SQL	B-Language
)	O
specific	O
to	O
each	O
data	O
source	O
.	O
</s>
<s>
The	O
first	O
attempt	O
came	O
in	O
1992	O
with	O
the	O
release	O
of	O
Database	O
Kit	O
(	O
DBKit	O
)	O
,	O
which	O
wrapped	O
an	O
object-oriented	B-Language
framework	O
around	O
any	O
database	O
.	O
</s>
<s>
Unfortunately	O
,	O
NEXTSTEP	B-Application
at	O
the	O
time	O
was	O
not	O
powerful	O
enough	O
and	O
DBKit	O
had	O
serious	O
design	O
flaws	O
.	O
</s>
<s>
NeXT	O
's	O
second	O
attempt	O
came	O
in	O
1994	O
with	O
the	O
Enterprise	B-General_Concept
Objects	I-General_Concept
Framework	I-General_Concept
(	O
EOF	O
)	O
version	O
1	O
,	O
a	O
complete	O
rewrite	O
that	O
was	O
far	O
more	O
modular	O
and	O
OpenStep	B-Operating_System
compatible	O
.	O
</s>
<s>
EOF	O
achieved	O
a	O
modest	O
level	O
of	O
popularity	O
in	O
the	O
financial	O
programming	O
community	O
in	O
the	O
mid-1990s	O
,	O
but	O
it	O
would	O
come	O
into	O
its	O
own	O
with	O
the	O
emergence	O
of	O
the	O
World	O
Wide	O
Web	O
and	O
the	O
concept	O
of	O
web	B-Application
applications	I-Application
.	O
</s>
<s>
With	O
the	O
addition	O
of	O
frameworks	O
to	O
do	O
state	O
management	O
,	O
load	O
balancing	O
and	O
dynamic	O
HTML	O
generation	O
,	O
NeXT	O
was	O
able	O
to	O
launch	O
the	O
first	O
object-oriented	B-Language
Web	B-Application
application	I-Application
server	O
,	O
WebObjects	B-Language
,	O
in	O
1996	O
,	O
with	O
EOF	O
at	O
its	O
core	O
.	O
</s>
<s>
In	O
2000	O
,	O
Apple	O
Inc	O
.	O
(	O
which	O
had	O
merged	O
with	O
NeXT	O
)	O
officially	O
dropped	O
EOF	O
as	O
a	O
standalone	O
product	O
,	O
meaning	O
that	O
developers	O
would	O
be	O
unable	O
to	O
use	O
it	O
to	O
create	O
desktop	O
applications	O
for	O
the	O
forthcoming	O
Mac	B-Application
OS	I-Application
X	I-Application
.	O
</s>
<s>
It	O
would	O
,	O
however	O
,	O
continue	O
to	O
be	O
an	O
integral	O
part	O
of	O
a	O
major	O
new	O
release	O
of	O
WebObjects	B-Language
.	O
</s>
<s>
WebObjects	B-Language
5	O
,	O
released	O
in	O
2001	O
,	O
was	O
significant	O
for	O
the	O
fact	O
that	O
its	O
frameworks	O
had	O
been	O
ported	O
from	O
their	O
native	O
Objective-C	B-Language
programming	I-Language
language	I-Language
to	O
the	O
Java	B-Language
language	I-Language
.	O
</s>
<s>
Critics	O
of	O
this	O
change	O
argue	O
that	O
most	O
of	O
the	O
power	O
of	O
EOF	O
was	O
a	O
side	O
effect	O
of	O
its	O
Objective-C	B-Language
roots	O
,	O
and	O
that	O
EOF	O
lost	O
the	O
beauty	O
or	O
simplicity	O
it	O
once	O
had	O
.	O
</s>
<s>
Third-party	O
tools	O
,	O
such	O
as	O
EOGenerator	O
,	O
help	O
fill	O
the	O
deficiencies	O
introduced	O
by	O
Java	B-Language
(	O
mainly	O
due	O
to	O
the	O
loss	O
of	O
categories	O
)	O
.	O
</s>
<s>
The	O
Objective-C	B-Language
code	O
base	O
was	O
re-introduced	O
with	O
some	O
modifications	O
to	O
desktop	O
application	O
developers	O
as	O
Core	B-Application
Data	I-Application
,	O
part	O
of	O
Apple	O
's	O
Cocoa	B-Operating_System
API	I-Operating_System
,	O
with	O
the	O
release	O
of	O
Mac	B-Application
OS	I-Application
X	I-Application
Tiger	I-Application
in	O
April	O
2005	O
.	O
</s>
<s>
Enterprise	O
Objects	O
provides	O
tools	O
and	O
frameworks	O
for	O
object-relational	B-General_Concept
mapping	I-General_Concept
.	O
</s>
<s>
The	O
technology	O
specializes	O
in	O
providing	O
mechanisms	O
to	O
retrieve	O
data	O
from	O
various	O
data	O
sources	O
,	O
such	O
as	O
relational	B-Application
databases	I-Application
via	O
JDBC	O
and	O
JNDI	O
directories	O
,	O
and	O
mechanisms	O
to	O
commit	O
data	O
back	O
to	O
those	O
data	O
sources	O
.	O
</s>
<s>
Central	O
to	O
this	O
mapping	O
is	O
a	O
model	O
file	O
(	O
an	O
"	O
EOModel	O
"	O
)	O
that	O
you	O
build	O
with	O
a	O
visual	O
tool	O
either	O
EOModeler	O
,	O
or	O
the	O
EOModeler	O
plug-in	O
to	O
Xcode	B-Operating_System
.	O
</s>
<s>
The	O
result	O
is	O
that	O
database	O
records	O
can	O
be	O
transposed	O
into	O
Java	B-Language
objects	O
.	O
</s>
<s>
In	O
designing	O
Enterprise	O
Objects	O
developers	O
can	O
leverage	O
the	O
object-oriented	B-Language
feature	O
known	O
as	O
inheritance	B-Language
.	O
</s>
<s>
While	O
this	O
kind	O
of	O
thinking	O
is	O
inherent	O
in	O
object-oriented	B-Language
design	O
,	O
relational	B-Application
databases	I-Application
have	O
no	O
explicit	O
support	O
for	O
inheritance	B-Language
.	O
</s>
<s>
That	O
is	O
,	O
you	O
can	O
design	O
database	O
tables	O
to	O
support	O
inheritance	B-Language
by	O
also	O
designing	O
enterprise	O
objects	O
that	O
map	O
to	O
multiple	O
tables	O
or	O
particular	O
views	O
of	O
a	O
database	O
table	O
.	O
</s>
<s>
An	O
Enterprise	O
Object	O
is	O
analogous	O
to	O
what	O
is	O
often	O
known	O
in	O
object-oriented	B-Language
programming	I-Language
as	O
a	O
business	B-General_Concept
object	I-General_Concept
a	O
class	O
which	O
models	O
a	O
physical	O
or	O
conceptual	O
object	O
in	O
the	O
business	O
domain	O
(	O
e.g.	O
</s>
<s>
Typically	O
,	O
an	O
enterprise	O
object	O
contains	O
key-value	O
pairs	O
that	O
represent	O
a	O
row	O
in	O
a	O
relational	B-Application
database	I-Application
.	O
</s>
<s>
More	O
precisely	O
,	O
an	O
Enterprise	O
Object	O
is	O
an	O
instance	O
of	O
a	O
class	O
that	O
implements	O
the	O
com.webobjects.eocontrol.EOEnterpriseObject	O
interface	O
.	O
</s>
<s>
Despite	O
their	O
common	O
origins	O
,	O
the	O
two	O
technologies	O
diverged	O
,	O
with	O
each	O
technology	O
retaining	O
a	O
subset	O
of	O
the	O
features	O
of	O
the	O
original	O
Objective-C	B-Language
code	O
base	O
,	O
while	O
adding	O
some	O
new	O
features	O
.	O
</s>
<s>
EOF	O
supports	O
custom	O
SQL	B-Language
;	O
shared	O
editing	O
contexts	O
;	O
nested	O
editing	O
contexts	O
;	O
and	O
pre-fetching	O
and	O
batch	O
faulting	O
of	O
relationships	O
,	O
all	O
features	O
of	O
the	O
original	O
Objective-C	B-Language
implementation	O
not	O
supported	O
by	O
Core	B-Application
Data	I-Application
.	O
</s>
<s>
Core	B-Application
Data	I-Application
also	O
does	O
not	O
provide	O
the	O
equivalent	O
of	O
an	O
EOModelGroup	O
—	O
the	O
NSManagedObjectModel	O
class	O
provides	O
methods	O
for	O
merging	O
models	O
from	O
existing	O
models	O
,	O
and	O
for	O
retrieving	O
merged	O
models	O
from	O
bundles	O
.	O
</s>
<s>
Core	B-Application
Data	I-Application
supports	O
fetched	O
properties	O
;	O
multiple	O
configurations	O
within	O
a	O
managed	O
object	O
model	O
;	O
local	O
stores	O
;	O
and	O
store	O
aggregation	O
(	O
the	O
data	O
for	O
a	O
given	O
entity	O
may	O
be	O
spread	O
across	O
multiple	O
stores	O
)	O
;	O
customization	O
and	O
localization	O
of	O
property	O
names	O
and	O
validation	O
warnings	O
;	O
and	O
the	O
use	O
of	O
predicates	O
for	O
property	O
validation	O
.	O
</s>
<s>
These	O
features	O
of	O
the	O
original	O
Objective-C	B-Language
implementation	O
are	O
not	O
supported	O
by	O
the	O
Java	B-Language
implementation	O
.	O
</s>
