gobject-introspection has two licenses; one for the typelib library,
and one for the tools.

The scanner (giscanner/) and typelib libraries (girepository/) are
licensed under the LGPLv2+.  See the file COPYING.LGPL.

The tools (tools/) are licensed under the GPLv2+.  See the file COPYING.GPL.

There is also some MIT code in giscanner/.  In general where
applicable files should have headers denoting their license status; if
they do not, please file a bug at http://bugzilla.gnome.org.