KeyFrog monitors the keyboard and visualizes its usage statistics. The user can obtain much information about keyboard activity: the intensity of keyboard usage, how was it distributed in time, which applications were used, etc. This may be very useful, for example, to developers to monitor their productivity. The environment being monitored is the X Window System (text applications are explicitly supported if run inside an X terminal).
Disko is a user interface application framework for the fast and simple development of flexible applications on embedded Linux systems, with a particular focus on interactive user interfaces. It is high-performance and easy to learn, and due to its architecture is well suited to creating complex applications.
wumwum is a window manager manager. The idea behind wumwum is to turn any EWMH-compliant window manager into a tiling manager a la "ion" or "awesome". wumwum works by using wmctrl, and adapts itself dynamically to the active window manager. All functionality from the underlying window manager is kept when under wumwum, making it ideal for beginners.
i3 is a dynamic tiling window manager. Its key features are correct implementation of Xinerama (workspaces are assigned to virtual screens, and it does the right thing when attaching new monitors) and XrandR support (which is still unfinished). Both horizontal and vertical columns can be used in tiling. There is a special focus is on writing clean, readable, and well documented code. i3 uses xcb for asynchronous communication with X11, and has several measures to be very fast. i3 is primarily targeted at advanced users and developers.
libNUI is a hardware accelerated GUI framework that makes it possible to build rich multi-platform applications based on 3D rendered dynamic layouts. Interfaces are built as a composition of widgets and behaviors, and the framework handles positioning, resizing, anchoring, and texture stretching. Objects are connected with synchronous events and delegates for mono-threaded communication, or asynchronous notifications and message queues are used for multi-threaded applications. It also supports strings (including Unicode), paths, files, data streams, fonts, threads, critical sections, audio buffer rendering, and more.
dualscreen-mouse-utils is a set of two useful utilities for dual screen setups (e.g. :0.0 and :0.1). mouse-switchscreen switches the cursor between X screens and remembers the last used position. mouse-wrapscreen wraps the mouse cursor from one screen to the other on the specified edge, even when the screens are configured to be apart and would normally be uncrossable.
Kittens is an application container that can embed X applications and steal them from your window manager in order to provide advanced window management options to any window manager. It can tab windows together, split to show them vertically side by side, and allow applications and splits to be resized with the mouse or keyboard. It works in environments such as GNOME, KDE, and XFCE. Kittens is also ideal for managing applications without having to use a mouse.