BRL-CAD interactively displaying, editing, and interrogating geometric models. This suite became known as BRL-CAD. Development on BRL-CAD as a package subsequently began in 1983; the first public release was made in 1984. BRL-CAD became an open-source project in December 2004. The BRL-CAD source code repository is the oldest known public version-controlled codebase in the world that's still under active development, dating back to 1983-12-16 00:10:31 UTC. BRL-CAD BRL-CAD is a constructive solid geometry (CSG) solid modeling computer-aided design (CAD) system. It includes an interactive geometry editor, ray tracing support for graphics rendering and geometric analysis, computer network distributed framebuffer support, scripting,
Computer-assisted proof the runtime environment and hardware. Other mathematicians believe that lengthy computer-assisted proofs should be regarded as "calculations", rather than "proofs": the proof algorithm itself should be proved valid, so that its use can then be regarded as a mere "verification". Arguments that computer-assisted proofs are subject to errors in their source programs, compilers, and hardware can be resolved by providing a formal proof of correctness for the computer program (an approach which was successfully applied to the four-color theorem in 2005) as well as replicating the result using different programming languages, different compilers, and different computer hardware. Another possible way