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.
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.
The primary aim of the Gtk+2 panel project is to provide a panel that reuses whatever is available (if it is not overkill) in the obvious way, such as subclassing GtkWidget instead of implementing applets, or by using a GtkBuilder file instead of defining a new format to customize the panel. This approach gives some additional advantages for free: you can use common tools in uncommon ways. Above all, you can use Glade to design your own panel. All the dependencies apart from GTK+ are (and hopefully will be) optional.
Histwi is a Linux desktop program for Twitter account management. It allows you to download and save all your Tweets to a database, view and export all saved Tweets to HTML or text files, compare your Following to Followers, follow/unfollow any your friends, track new followers and unfollowers, and manage multiple Twitter accounts.