<s>
The	O
PHP	B-Application
Extension	I-Application
and	I-Application
Application	I-Application
Repository	I-Application
,	O
or	O
PEAR	B-Application
,	O
is	O
a	O
repository	O
of	O
PHP	B-Application
software	O
code	O
.	O
</s>
<s>
Stig	O
S	O
.	O
Bakken	O
founded	O
the	O
PEAR	B-Application
project	O
in	O
1999	O
to	O
promote	O
the	O
re-use	O
of	O
code	O
that	O
performs	O
common	O
functions	O
.	O
</s>
<s>
The	O
project	O
seeks	O
to	O
provide	O
a	O
structured	O
library	B-Library
of	O
code	O
,	O
maintain	O
a	O
system	O
for	O
distributing	O
code	O
and	O
for	O
managing	O
code	B-Library
packages	I-Library
,	O
and	O
promote	O
a	O
standard	O
coding	O
style	O
.	O
</s>
<s>
Though	O
community-driven	O
,	O
the	O
PEAR	B-Application
project	O
has	O
a	O
PEAR	B-Application
Group	O
which	O
serves	O
as	O
the	O
governing	O
body	O
and	O
takes	O
care	O
of	O
administrative	O
tasks	O
.	O
</s>
<s>
Each	O
PEAR	B-Application
code	B-Library
package	I-Library
comprises	O
an	O
independent	O
project	O
under	O
the	O
PEAR	B-Application
umbrella	O
.	O
</s>
<s>
A	O
PEAR	B-Application
package	O
is	O
distributed	O
as	O
a	O
gzipped	O
tar	B-Application
file	I-Application
.	O
</s>
<s>
Each	O
archive	O
consists	O
of	O
source	O
code	O
written	O
in	O
PHP	B-Application
,	O
.	O
</s>
<s>
Many	O
PEAR	B-Application
packages	O
can	O
readily	O
be	O
used	O
by	O
developers	O
as	O
ordinary	O
third	O
party	O
code	O
via	O
simple	O
include	O
statements	O
in	O
PHP	B-Application
.	O
</s>
<s>
More	O
elegantly	O
,	O
the	O
PEAR	B-Application
package	B-Application
manager	I-Application
which	O
comes	O
with	O
PHP	B-Application
by	O
default	O
may	O
be	O
used	O
to	O
install	O
PEAR	B-Application
packages	O
so	O
that	O
the	O
extra	O
functionality	O
provided	O
by	O
the	O
package	O
appears	O
as	O
an	O
integrated	O
part	O
of	O
the	O
PHP	B-Application
installation	O
.	O
</s>
<s>
Unlike	O
the	O
Comprehensive	B-Language
Perl	I-Language
Archive	I-Language
Network	I-Language
(	O
CPAN	B-Language
)	O
archives	O
,	O
,	O
PEAR	B-Application
packages	O
do	O
not	O
have	O
implicit	O
dependencies	O
so	O
that	O
a	O
package	O
's	O
placement	O
in	O
the	O
PEAR	B-Application
package	O
tree	O
does	O
not	O
relate	O
to	O
code	O
dependencies	O
.	O
</s>
<s>
Rather	O
,	O
PEAR	B-Application
packages	O
must	O
explicitly	O
declare	O
all	O
dependencies	O
on	O
other	O
PEAR	B-Application
packages	O
.	O
</s>
<s>
The	O
PEAR	B-Application
base	O
classes	O
contain	O
code	O
for	O
simulating	O
object-oriented	B-Language
destructors	B-Language
and	O
consistent	O
error-handling	O
.	O
</s>
<s>
Packages	O
exist	O
for	O
many	O
basic	O
PHP	B-Application
functions	O
including	O
authentication	O
,	O
caching	B-Protocol
,	O
database	O
access	O
,	O
encryption	O
,	O
configuration	O
,	O
HTML	B-Language
,	O
web	O
services	O
and	O
XML	B-Protocol
.	O
</s>
<s>
PEAR	B-Application
means	O
“	O
PHP	B-Application
Extension	O
and	O
Application	O
Repository.	O
”	O
It	O
is	O
a	O
framework	O
and	O
distribution	O
system	O
for	O
reusable	O
PHP	B-Application
components	O
.	O
</s>
<s>
It	O
extends	O
PHP	B-Application
and	O
gives	O
a	O
higher	O
level	O
of	O
programming	O
for	O
all	O
web	O
developers	O
.	O
</s>
<s>
PEAR	B-Application
is	O
divided	O
into	O
three	O
different	O
classes	O
that	O
are	O
:	O
PEAR	B-Application
Core	O
Components	O
,	O
PEAR	B-Application
Packages	O
,	O
and	O
PECL	O
Packages	O
.	O
</s>
<s>
The	O
PEAR	B-Application
Packages	O
include	O
functionality	O
giving	O
for	O
authentication	O
,	O
networking	O
,	O
and	O
file	O
system	O
features	O
and	O
tools	O
for	O
working	O
with	O
HTML	B-Language
and	O
XML	B-Protocol
templates	O
.	O
</s>
<s>
The	O
PEAR	B-Application
package	B-Application
manager	I-Application
provides	O
a	O
standardized	O
way	O
to	O
install	O
,	O
uninstall	O
,	O
or	O
upgrade	O
with	O
new	O
PEAR	B-Application
packages	O
or	O
PECL	O
extensions	O
.	O
</s>
<s>
The	O
PEAR	B-Application
package	B-Application
manager	I-Application
is	O
run	O
from	O
the	O
command	O
line	O
using	O
the	O
pear	B-Application
command	O
.	O
</s>
<s>
Usually	O
it	O
is	O
therefore	O
only	O
the	O
server	O
administrator	O
who	O
can	O
alter	O
the	O
installed	O
base	O
of	O
PEAR	B-Application
and	O
PECL	O
extensions	O
.	O
</s>
<s>
On	O
PHP	B-Application
installations	O
running	O
on	O
Linux	O
,	O
the	O
PEAR	B-Application
package	B-Application
manager	I-Application
is	O
ready	O
for	O
usage	O
by	O
default	O
,	O
but	O
on	O
Windows	O
the	O
PEAR	B-Application
package	B-Application
manager	I-Application
is	O
only	O
available	O
after	O
running	O
a	O
batch	O
file	O
called	O
go-pear.bat	O
.	O
</s>
<s>
With	O
Pyrus	O
an	O
attempt	O
was	O
undertaken	O
to	O
redesign	O
and	O
improve	O
PEAR	B-Application
from	O
the	O
ground	O
up	O
for	O
PHP	B-Application
5.3	O
or	O
newer	O
.	O
</s>
<s>
Pyrus	O
can	O
be	O
used	O
to	O
install	O
packages	O
from	O
PEAR	B-Application
channels	O
.	O
</s>
<s>
The	O
last	O
release	O
is	O
from	O
March	O
2011	O
and	O
its	O
development	O
might	O
have	O
been	O
discontinued	O
due	O
to	O
the	O
popularity	O
of	O
Composer	B-Application
.	O
</s>
<s>
With	O
Composer	B-Application
there	O
is	O
an	O
alternative	O
available	O
for	O
managing	O
packages	O
for	O
a	O
PHP	B-Application
project	O
.	O
</s>
<s>
Composer	B-Application
also	O
supports	O
the	O
installation	O
of	O
PEAR	B-Application
packages	O
.	O
</s>
<s>
Some	O
people	O
of	O
the	O
PHP	B-Application
community	O
argue	O
for	O
replacing	O
PEAR	B-Application
in	O
favor	O
of	O
composer	B-Application
.	O
</s>
<s>
The	O
PHP	B-Application
Extension	O
Community	O
Library	B-Library
(	O
PECL	O
)	O
,	O
(	O
pronounced	O
'	O
pickle	O
 '	O
)	O
is	O
conceptually	O
very	O
similar	O
to	O
PEAR	B-Application
,	O
and	O
indeed	O
PECL	O
modules	O
are	O
installed	O
with	O
the	O
PEAR	B-Application
Package	B-Application
Manager	I-Application
.	O
</s>
<s>
PECL	O
contains	O
C	B-Language
extensions	O
for	O
compiling	O
into	O
PHP	B-Application
.	O
</s>
<s>
As	O
C	B-Language
programs	I-Language
,	O
PECL	O
extensions	O
run	O
more	O
efficiently	O
than	O
PEAR	B-Application
packages	O
.	O
</s>
<s>
PECL	O
includes	O
modules	O
for	O
XML-parsing	O
,	O
access	O
to	O
additional	O
databases	O
,	O
mail-parsing	O
,	O
embedding	O
Perl	B-Language
or	O
Python	B-Language
in	O
PHP	B-Application
scripts	I-Application
and	O
for	O
compiling	O
PHP	B-Application
scripts	I-Application
.	O
</s>
<s>
PECL	O
spun	O
off	O
from	O
the	O
PEAR	B-Application
Project	O
in	O
October	O
2003	O
.	O
</s>
<s>
Originally	O
it	O
was	O
called	O
the	O
PEAR	B-Application
Extension	O
Code	B-Library
Library	I-Library
,	O
but	O
it	O
now	O
operates	O
independently	O
of	O
PEAR	B-Application
.	O
</s>
<s>
PECL	O
extensions	O
are	O
documented	O
alongside	O
standard	O
extensions	O
within	O
the	O
PHP	B-Application
Manual	O
,	O
so	O
there	O
is	O
no	O
special	O
manual	O
for	O
PECL	O
extensions	O
.	O
</s>
<s>
Also	O
,	O
several	O
extensions	O
began	O
their	O
development	O
cycle	O
in	O
PECL	O
and	O
ended	O
up	O
in	O
core	O
(	O
the	O
distributed	O
PHP	B-Application
source	O
)	O
and	O
in	O
many	O
of	O
these	O
cases	O
the	O
PECL	O
versions	O
become	O
unmaintained	O
.	O
</s>
