OCT is a tool that implements the logical system OCLP (Ordered Choice Logic Programming). The logic itself is described by a series of papers. OCT itself is originally described in Implementing OCLP as a front-end for Answer Set Solvers: From Theory to Practice which was presented at ASP03.
It translates OCLP programs into semi-negative logic programs which can then be run through a standard answer set solver. It can also be built with an integral copy of Smodels so it just outputs the answer sets of the input program. For a more detailed description see the source code.
Sure! OCT is made available under the GPL and can be freely down-loaded here.
It's quite straight forward (assuming you think compiling anything from source is conceptually not too difficult)
Also see the 'installing' file.
OCT was developed on an x86 system running Red Hat 7.3 GNU/Linux. It should build and run on any modern POSIX compatible system (IE if you are running any modern UNIX like system you should be OK). It currently requires g++ but could easily be compiled using any modern C++ compiler (IE supports Templating and the STL).
For practical, technological, financial and moral reasons this software has not been developed on any Microsoft operating system and we do not envisage this changing. If you have to use Windows et al. then there is nothing to stop you using a UNIX compatibility layer like Cygwin or porting it to Windows yourself (this shouldn't be too difficult). If anyone does port a copy to Windows, we will happily make changes to the next version so that it will compile on Windows in an unpatched version.
OCT was written and is maintained by Martin Brain (e-mail address included with the source code). The initial development was (very kindly) sponsored by the University of Bath Department of Computing Science and it is now maintained in Martin's free time.