@ (monkey-tail) is a simple collection of simple commands. Built-in commands include listing of memory usage and open files for a process (by name or PID), running processes detached from a terminal, and running a program only once. @ can merge external pieces of code into itself to provide extra commands. Additionally, these "externals" can then be updated from their source. Currently there are externals available for extracting archive files (including nested archives), setting the GNOME desktop wallpaper image, and for replicating @ to another host via SSH. Externals can easily be written, as they are simply collections of Bash functions. It is completely self contained and self modifying, and is implemented in a single file.
The ATA over Ethernet Tools are intended for use in conjunction with an ATA over Ethernet (AoE) driver for a Linux 2.6 kernel, called "aoe". The tools perform simple tasks like listing available devices, triggering device discovery, and restricting the network interfaces on which AoE is performed.
Abmash provides Web application automation based on visible rendered output. It is all about interacting with a browser as humans would do, including AJAX and forms. It lets you perform tasks like "Click the red button", "Give me all text elements directly below an image", or "Click 'Login' and wait until the login form is loaded, then type in my credentials and submit the form".
AldoContent is a lightweight CMS focused on usability and simplicity. It is designed for multilingual Web sites and can have sections with public and private content. It has file management, is extensible with plugins, and uses gettext for localization. Is written in PHP for a MySQL backend.
ArahPaint4 is a raster based paint program for drawing images in repeat, mainly for textiles. It includes a graphical image browser, works well on large images, allows limited image palettes, and supports drawing with non-square pixels. It is used in industry by over 300 textile mills, schools, and designers.