0 A.D. (pronounced "zero ey-dee") is a cross-platform real-time strategy (RTS) game of ancient warfare. It's a historically-based war/economy game that allows players to relive or rewrite the history of ancient civilizations, each depicted at their peak of economic growth and military prowess.
ACFTools is a utility for manipulating X-Plane flight simulator aircraft and weapon models without using its Plane Maker. It can decode both Apple and Intel ACF/WPN formats into plain text files with a syntax similar to C, which can be edited and then re-converted into binary data. It is able to extract almost complete 3D models of aircraft (fuselage, floats, tanks, wings, stabs, propellers, engines) and write it in AC3D modeler format. Edited 3D parts can then be merged into plain text and consequently converted into binary ACF files.
ACL2 is a mathematical logic, programming language, and mechanical theorem prover based on the applicative subset of Common Lisp. It is an "industrial-strength" version of the NQTHM or Boyer/Moore theorem prover, and has been used for the formal verification of commercial microprocessors, the Java Virtual Machine, interesting algorithms, and so forth.
APBS is a software package for the numerical solution of the Poisson-Boltzmann equation (PBE), one of the most popular continuum models for describing electrostatic interactions between molecular solutes in salty, aqueous media. Continuum electrostatics plays an important role in several areas of biomolecular simulation, including simulation of diffusional processes to determine ligand-protein and protein-protein binding kinetics, implicit solvent molecular dynamics of biomolecules, solvation and binding energy calculations to determine ligand-protein and protein-protein equilibrium binding constants and aid in rational drug design, and biomolecular titration studies.