Qt - Powerful, flexible and easy to use, Qt will help you not only meet your tight deadline, but also reduce the maintainable code by an astonishing percentage.
Linx - Integration and automation platform for growing businesses
wxWidgets - wxWidgets: Cross-Platform GUI Library
DHTMLX Suite - DHTMLX Suite offers JavaScript UI library for building cross-browser web and mobile applications.
FLTK - Fast Light Toolkit - Fast Light Toolkit (FLTK)
PHPmaker - PHPMaker is a powerful automation tool that can generate a full set of PHP quickly from MySQL, PostgreSQL, Oracle, Microsoft Access, Microsoft SQL Server and SQLite databases.