“GTK+, the core toolkit of a large number of Linux graphical
applications, was, two short years ago, exclusively used by a
single program, the GNU Image Manipulation Program, or the GIMP.
From its beginnings as an X toolkit coded from scratch, enormous
resources have been sunk into creating what is today called the
GIMP Tool Kit. In two short years, this X library has gone from
relative obscurity to being one of the foundations of the popular
GNOME desktop environment. GTK+ forms a significant part of the
functionality of end-user Linux applications and has far exceeded
the original expectations of the authors.“
“Years ago, the most important X toolkit was called Motif. Motif
was the core of almost all commercial and many non-commercial X
applications. This was a significant problem, because Motif was
until recently proprietary software in every sense of the word:
source code was unavailable, and the so-called “Open Group” was
unresponsive to developers and end users. The only free alternative
to Motif, Lesstif, was inadequate at the time to compile any but
the most simple applications. At the time, a huge amount of
rhetoric was being spilled over the subject.”
“In fact, Motif was one of the first major obstacles to the
progress of Linux in general. It was the most advanced toolkit of
its time, and thus many applications were coded against it. Coding
a replacement for Motif was an enormous undertaking. Other toolkits
(QT, for instance) were either facing similar problems with
licensing, or incompleteness, or simple technical inflexibility or
lack of publicity.”