FLTK is a cross-platform C++ GUI toolkit for UNIX®/Linux® (X11), Microsoft® Windows®, and macOS®. FLTK provides modern GUI functionality without the bloat and supports 3D graphics via OpenGL® and its built-in GLUT emulation. FLTK is designed to be small and modular enough to be statically linked, but works fine as a shared library. FLTK also includes an excellent UI builder called FLUID that can b