IBM developerWorks: GNOMEnclature: Getting Ready for GNOME 2, Part 2

“In this article, we’re going to take a look at the GLib object
system, also called ‘GObject’, which up until recently used to be
part of GTK+. But before taking a look at the new object system in
Glib 2.0, we need to address a more fundamental issue — what
exactly is an “object system” and why does it exist? After all,
isn’t C a non-object oriented language? It is possible to write
object-oriented programs in C, or must one use C++ instead?

“The answer is that it is possible to write object-oriented
programs in C. However, because the concept of object isn’t a part
of the C language specification, an external library is required to
provide this support. In this article, we use the term ‘object
system’ to describe a library that provides the foundation required
for OOP programming, and Glib is an example of such a library. Glib
provides a C implementation of classes, inheritance, reference
counting, signals, interfaces, and object properties. By using
Glib, C programmers can write object-oriented programs with
ease.

“So, it is possible to write object-oriented programs in C.
However, you may be wondering why the GTK+ developers didn’t just
go ahead and use C++ instead. Without covering every possible
explanation, here are a few reasons why it makes sense to have an
object system for C. For one, there are many developers who simply
prefer C to C++. In other situations, using a C++ compiler may not
be an option due to project or platform constraints. Whatever the
reason, having an object system for C opens up OOP programming (and
GNOME programming in particular) to a wider number of potential
developers, and for that we’re grateful…”

Complete
Story