Otk (Open Tool Kit) - portable library for graphical user interfaces (GUI's) based on C and OpenGL. Emphasizes simplicity without eliminating capability. Supports panel's, text label's, buttons, form boxes, pull-down menu's, slider control's, etc..
Open source project that offer summary and download services on this page is a project that carry out their development work on other open source development sites. Their work is linked to this page via a feature called OFI, and their work is not carried out here on OSDN site.