GLib provides advanced data structures, including balanced binary trees, hash tables, N-ary trees, memory chunks, single and double linked lists and dynamic strings and string utilities. Cache, which provides memory management, is also included.

GLib implements numerous functions, including thread programming and related facilities (such as mutexes, secure memory pools, message passing and timing) and message passing facilities, like input/output (I/O) channels.

As a library, GLib offers features that may be shared by other programs. Data types provided by GLib may be used by a variety of programming languages with GTK+ wrapping.

GLib runs on Unix-like platforms, Windows, OS/2 and BeOS. Additionally, GLib has cross-platform capabilities, which allow written GLib applications to run on any of these platforms, thus minimizing rewrites.