GTK+ (GIMP Toolkit) is a cross-platform widget toolkit for creating graphical user interface. Developed by GNOME Foundation
License: Open Source
wxWidgets and GTK+ are both powerful GUI toolkits, with wxWidgets offering a more native look across platforms and a broader programming language support, while GTK+ provides a modern widget set and is deeply integrated with the GNOME desktop environment. GTK+ may be more resource-intensive and less cross-platform friendly, whereas wxWidgets is preferred for applications needing a lightweight solution with native performance.