We plan to migrate to GTK+3. Due to the generally forward-compatible programming style of SeekMIDI, this should be an easy task, requiring a switch of all occurences of "Gtk2" to "Gtk3" and updating the documentation to reflect the change.
After more research, not all distributions contain the Perl binding for GTK+3, including Arch, the main development system. Obviously, we won't be switching right now.
We plan to migrate to GTK+3. Due to the generally forward-compatible programming style of SeekMIDI, this should be an easy task, requiring a switch of all occurences of "Gtk2" to "Gtk3" and updating the documentation to reflect the change.