<s>
In	O
computer	B-General_Concept
programming	I-General_Concept
,	O
a	O
software	B-Architecture
framework	I-Architecture
is	O
an	O
abstraction	B-Application
in	O
which	O
software	O
,	O
providing	O
generic	O
functionality	O
,	O
can	O
be	O
selectively	O
changed	O
by	O
additional	O
user-written	O
code	O
,	O
thus	O
providing	O
application-specific	O
software	O
.	O
</s>
<s>
It	O
provides	O
a	O
standard	O
way	O
to	O
build	O
and	O
deploy	O
applications	O
and	O
is	O
a	O
universal	O
,	O
reusable	O
software	O
environment	O
that	O
provides	O
particular	O
functionality	O
as	O
part	O
of	O
a	O
larger	O
software	B-Device
platform	I-Device
to	O
facilitate	O
the	O
development	O
of	O
software	B-Application
applications	I-Application
,	O
products	O
and	O
solutions	O
.	O
</s>
<s>
Software	B-Architecture
frameworks	I-Architecture
may	O
include	O
support	O
programs	O
,	O
compilers	O
,	O
code	B-Library
libraries	I-Library
,	O
toolsets	O
,	O
and	O
application	B-Application
programming	I-Application
interfaces	I-Application
(	O
APIs	B-Application
)	O
that	O
bring	O
together	O
all	O
the	O
different	O
components	O
to	O
enable	O
development	O
of	O
a	O
project	O
or	O
system	O
.	O
</s>
<s>
Frameworks	O
have	O
key	O
distinguishing	O
features	O
that	O
separate	O
them	O
from	O
normal	O
libraries	B-Library
:	O
</s>
<s>
inversion	B-Language
of	I-Language
control	I-Language
:	O
In	O
a	O
framework	O
,	O
unlike	O
in	O
libraries	B-Library
or	O
in	O
standard	O
user	O
applications	O
,	O
the	O
overall	O
program	O
's	O
flow	O
of	O
control	O
is	O
not	O
dictated	O
by	O
the	O
caller	O
,	O
but	O
by	O
the	O
framework	O
.	O
</s>
<s>
extensibility	B-Architecture
:	O
A	O
user	O
can	O
extend	O
the	O
framework	O
–	O
usually	O
by	O
selective	O
overriding	O
–	O
or	O
programmers	O
can	O
add	O
specialized	O
user	O
code	O
to	O
provide	O
specific	O
functionality	O
.	O
</s>
<s>
The	O
designers	O
of	O
software	B-Architecture
frameworks	I-Architecture
aim	O
to	O
facilitate	O
software	O
developments	O
by	O
allowing	O
designers	O
and	O
programmers	O
to	O
devote	O
their	O
time	O
to	O
meeting	O
software	O
requirements	O
rather	O
than	O
dealing	O
with	O
the	O
more	O
standard	O
low-level	O
details	O
of	O
providing	O
a	O
working	O
system	O
,	O
thereby	O
reducing	O
overall	O
development	O
time	O
.	O
</s>
<s>
For	O
example	O
,	O
a	O
team	O
using	O
a	O
web	B-Application
framework	I-Application
to	O
develop	O
a	O
banking	O
website	O
can	O
focus	O
on	O
writing	O
code	O
particular	O
to	O
banking	O
rather	O
than	O
the	O
mechanics	O
of	O
request	O
handling	O
and	O
state	B-Application
management	I-Application
.	O
</s>
<s>
Further	O
,	O
due	O
to	O
the	O
complexity	O
of	O
their	O
APIs	B-Application
,	O
the	O
intended	O
reduction	O
in	O
overall	O
development	O
time	O
may	O
not	O
be	O
achieved	O
due	O
to	O
the	O
need	O
to	O
spend	O
additional	O
time	O
learning	O
to	O
use	O
the	O
framework	O
;	O
this	O
criticism	O
is	O
clearly	O
valid	O
when	O
a	O
special	O
or	O
new	O
framework	O
is	O
first	O
encountered	O
by	O
development	O
staff	O
.	O
</s>
<s>
An	O
example	O
of	O
that	O
would	O
be	O
how	O
the	O
user	O
interface	O
in	O
such	O
an	O
application	B-Application
package	I-Application
as	O
an	O
office	O
suite	O
grows	O
to	O
have	O
common	O
look	O
,	O
feel	O
,	O
and	O
data-sharing	O
attributes	O
and	O
methods	O
,	O
as	O
the	O
once	O
disparate	O
bundled	O
applications	O
,	O
grow	O
unified	O
into	O
a	O
suite	O
that	O
is	O
tighter	O
and	O
smaller	O
;	O
the	O
newer/evolved	O
suite	O
can	O
be	O
a	O
product	O
that	O
shares	O
integral	O
utility	O
libraries	B-Library
and	O
user	O
interfaces	O
.	O
</s>
<s>
The	O
elegance	O
issue	O
is	O
why	O
relatively	O
few	O
software	B-Architecture
frameworks	I-Architecture
have	O
stood	O
the	O
test	O
of	O
time	O
:	O
the	O
best	O
frameworks	O
have	O
been	O
able	O
to	O
evolve	O
gracefully	O
as	O
the	O
underlying	O
technology	O
on	O
which	O
they	O
were	O
built	O
advanced	O
.	O
</s>
<s>
Software	B-Architecture
frameworks	I-Architecture
typically	O
contain	O
considerable	O
housekeeping	O
and	O
utility	O
code	O
in	O
order	O
to	O
help	O
bootstrap	O
user	O
applications	O
,	O
but	O
generally	O
focus	O
on	O
specific	O
problem	O
domains	O
,	O
such	O
as	O
:	O
</s>
<s>
Cactus	B-Application
Framework	I-Application
–	O
High	O
performance	O
scientific	O
computing	O
.	O
</s>
<s>
Application	B-Application
framework	I-Application
–	O
General	O
GUI	O
applications	O
.	O
</s>
<s>
According	O
to	O
Pree	O
,	O
software	B-Architecture
frameworks	I-Architecture
consist	O
of	O
frozen	O
spots	O
and	O
hot	O
spots	O
.	O
</s>
<s>
These	O
remain	O
unchanged	O
(	O
frozen	O
)	O
in	O
any	O
instantiation	O
of	O
the	O
application	B-Application
framework	I-Application
.	O
</s>
<s>
In	O
an	O
object-oriented	B-Language
environment	O
,	O
a	O
framework	O
consists	O
of	O
abstract	O
and	O
concrete	O
classes	O
.	O
</s>
<s>
Instantiation	O
of	O
such	O
a	O
framework	O
consists	O
of	O
composing	B-Language
and	O
subclassing	O
the	O
existing	O
classes	O
.	O
</s>
<s>
When	O
developing	O
a	O
concrete	O
software	O
system	O
with	O
a	O
software	B-Architecture
framework	I-Architecture
,	O
developers	O
utilize	O
the	O
hot	O
spots	O
according	O
to	O
the	O
specific	O
needs	O
and	O
requirements	O
of	O
the	O
system	O
.	O
</s>
<s>
Software	B-Architecture
frameworks	I-Architecture
rely	O
on	O
the	B-Language
Hollywood	I-Language
Principle	I-Language
:	O
"	O
Do	O
n't	O
call	O
us	O
,	O
we	O
'll	O
call	O
you.	O
"	O
</s>
