libgtk2.0-dev

Package contains libraries, required by other applications as dependencies. Do not install separately.

Development files for the GTK+ library
The GTK+ is a multi-platform toolkit for creating graphical user
interfaces. Offering a complete set of widgets, the GTK+ is suitable
for projects ranging from small one-off tools to complete application
suites.
.
This package contains the header files and static libraries which is
needed for developing the GTK+ applications.