Ballista testing works by bombarding a software module with combinations of exceptional and acceptable input values. The reaction of the system is measured for either catastrophic OS failure (generally in the form of a machine reboot), a task "hang" (detected by a watchdog timer), or a task "abort" (detected by observing that a child process terminates abnormally).

Ballista is the product of many years of research in the area of dependability, and particular fault injection, at Carnegie Mellon's Institute for Complex Engineered Systems. The focus of our research has been on repeatability and portability. A complete survey of other approaches is beyond the scope of this FAQ, but can be found in our various publications. See similar questions...

When the catapult/ballista/cannon is built, it will already be carrying full ammo. To find out how much ammo the weapon is carrying, select the weapon and take a look at the small number that is above it's status dot. When this number is at 0, move the weapon back to a production house that has ammo outside it and then click on reload. To fire the weapon, move it to a suitable range of an enemy tower or castle and then click on the tower or castle with the right mouse button. See similar questions...

The goal of the Ballista project is to automatically test off-the-shelf software components for robustness problems. These results will apply to as broad a class of software components as possible, but in general will work best on modules that take all inputs from a parameter list. While we also are looking at ways to automatically harden components to prevent robustness failures, in the near term only automated testing will be useful for industry projects. See similar questions...

You can download Ballista for free under the GPL. See the Ballista home page for pointers to the download site. See similar questions...

Zanfel works safely into the dermal layer of your skin, binds to the urushiol oil, and, when rinsed off, takes the oil with it down the drain. See similar questions...