<s>
GLib	B-Language
is	O
a	O
bundle	O
of	O
three	O
(	O
formerly	O
five	O
)	O
low-level	O
system	B-Library
libraries	I-Library
written	O
in	O
C	B-Language
and	O
developed	O
mainly	O
by	O
GNOME	O
.	O
</s>
<s>
GLib	B-Language
's	O
code	O
was	O
separated	O
from	O
GTK	B-Application
,	O
so	O
it	O
can	O
be	O
used	O
by	O
software	O
other	O
than	O
GNOME	O
and	O
has	O
been	O
developed	O
in	O
parallel	O
ever	O
since	O
.	O
</s>
<s>
GLib	B-Language
provides	O
advanced	O
data	O
structures	O
,	O
such	O
as	O
memory	O
chunks	O
,	O
doubly	O
and	O
singly	O
linked	B-Data_Structure
lists	I-Data_Structure
,	O
hash	B-Algorithm
tables	I-Algorithm
,	O
dynamic	O
strings	O
and	O
string	O
utilities	O
,	O
such	O
as	O
a	O
lexical	B-Application
scanner	B-Application
,	O
string	O
chunks	O
(	O
groups	O
of	O
strings	O
)	O
,	O
dynamic	O
arrays	B-Data_Structure
,	O
balanced	O
binary	O
trees	O
,	O
N-ary	B-Data_Structure
trees	I-Data_Structure
,	O
quarks	O
(	O
a	O
two-way	O
association	O
of	O
a	O
string	O
and	O
a	O
unique	O
integer	O
identifier	O
)	O
,	O
keyed	O
data	O
lists	O
,	O
relations	O
,	O
and	O
tuples	B-Application
.	O
</s>
<s>
Caches	B-General_Concept
provide	O
memory	O
management	O
.	O
</s>
<s>
GLib	B-Language
implements	O
functions	O
that	O
provide	O
threads	B-Operating_System
,	O
thread	B-Operating_System
programming	O
and	O
related	O
facilities	O
such	O
as	O
primitive	O
variable	O
access	O
,	O
mutexes	B-Operating_System
,	O
asynchronous	O
queues	B-Application
,	O
secure	O
memory	B-General_Concept
pools	I-General_Concept
,	O
message	B-Architecture
passing	I-Architecture
and	O
logging	O
,	O
hook	O
functions	O
(	O
callback	O
registering	O
)	O
and	O
timers	O
.	O
</s>
<s>
GLib	B-Language
also	O
includes	O
message	B-Architecture
passing	I-Architecture
facilities	O
such	O
as	O
byte	O
order	O
conversion	O
and	O
I/O	O
channels	O
.	O
</s>
<s>
Some	O
other	O
features	O
of	O
GLib	B-Language
include	O
:	O
</s>
<s>
The	O
GLib	B-Language
package	O
consisted	O
of	O
five	O
libraries	B-Library
,	O
but	O
they	O
were	O
all	O
merged	O
into	O
one	O
library	B-Library
,	O
since	O
then	O
named	O
simply	O
GLib	B-Language
,	O
and	O
are	O
no	O
longer	O
sustained	O
as	O
standalone	O
libraries	B-Library
.	O
</s>
<s>
The	O
original	O
libraries	B-Library
were	O
:	O
</s>
<s>
Of	O
these	O
,	O
three	O
continue	O
to	O
reside	O
in	O
distinct	O
subdirectories	O
of	O
the	O
source	O
tree	O
,	O
and	O
so	O
can	O
be	O
thought	O
of	O
as	O
discrete	O
components	O
:	O
GLib	B-Language
,	O
GObject	B-Language
,	O
and	O
GIO	B-Language
.	O
</s>
<s>
These	O
can	O
be	O
thought	O
of	O
as	O
a	O
software	O
stack	O
:	O
GObject	B-Language
relies	O
on	O
GLib	B-Language
,	O
and	O
GIO	B-Language
provides	O
higher-level	O
functionality	O
that	O
uses	O
both	O
.	O
</s>
<s>
GLib	B-Language
began	O
as	O
part	O
of	O
the	O
GTK+	B-Application
project	O
,	O
now	O
named	O
GTK	B-Application
.	O
</s>
<s>
However	O
,	O
before	O
releasing	O
GTK+	B-Application
version	O
2	O
,	O
the	O
project	O
's	O
developers	O
decided	O
to	O
separate	O
code	O
from	O
GTK+	B-Application
that	O
was	O
not	O
for	O
graphical	B-Application
user	I-Application
interfaces	I-Application
(	O
GUIs	B-Application
)	O
,	O
thus	O
creating	O
GLib	B-Language
as	O
a	O
separate	O
software	O
bundle	O
.	O
</s>
<s>
GLib	B-Language
was	O
released	O
as	O
a	O
separate	O
library	B-Library
so	O
other	O
developers	O
,	O
those	O
not	O
using	O
the	O
GUI-related	O
parts	O
of	O
GTK+	B-Application
,	O
could	O
use	O
the	O
non-GUI	O
parts	O
of	O
the	O
library	B-Library
without	O
the	O
overhead	O
of	O
depending	O
on	O
the	O
full	O
GUI	B-Application
library	B-Library
.	O
</s>
<s>
Since	O
GLib	B-Language
is	O
a	O
cross-platform	B-Operating_System
library	B-Library
,	O
applications	O
using	O
it	O
to	O
interface	O
with	O
the	O
operating	B-General_Concept
system	I-General_Concept
are	O
usually	O
portable	O
across	O
different	O
operating	B-General_Concept
systems	I-General_Concept
without	O
major	O
changes	O
.	O
</s>
<s>
Glib	B-Language
is	O
undergoing	O
active	O
development	O
.	O
</s>
<s>
Other	O
libraries	B-Library
provide	O
low-level	O
functions	O
and	O
implementations	O
of	O
data	O
structures	O
,	O
including	O
:	O
</s>
<s>
The	O
Apache	B-Language
Portable	I-Language
Runtime	I-Language
and	O
Apple	O
Core	B-Operating_System
Foundation	I-Operating_System
have	O
a	O
large	O
functional	O
overlap	O
with	O
GLib	B-Language
,	O
and	O
provide	O
many	O
similar	O
OS-portable	O
threading	O
,	O
network	O
and	O
data	O
structure	O
implementations	O
in	O
C	B-Language
.	O
</s>
