GTKMathplot is an interactive plotting program based on GTK+ and the Cairo graphics library. It can display bidimensional curves, tridimensional curves, and surfaces from Cartesian or parametric equations describing the mathematical objects you would like to visualize. It is designed to be intuitive for high school students with good mathematical knowledge. University students of engineering, physics, mathematics, or natural sciences should need no explanation at all to start using it proficiently.
DeforaOS Surfer is a portable Web browser, supporting tabbed browsing on a number of platforms, including embedded environments. It notably supports either XULRunner (Mozilla), WebKit, libGtkHtml, or its own lightweight implementation as the actual rendering engine to display pages.