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.
gwcalc is a front-end for the Wcalc command line calculator. Its main features are menu access to all functions defined in Wcalc, menu access to a huge number of constants defined in Wcalc, intuitive entry of formulas, easy editing and 're-evaluation', and easy conversion between decimal, hex, octal, and binary, both in input and output. It works with fractional numbers in all bases, is very configurable, and is easy to use.