The Ares was a proposed intercontinental ballistic missile (ICBM) derived from the Titan II missile. It was a single stage rocket with a high-performance engine to increase the rocket's specific impulse. Both Aerojet and Rocketdyne carried out engine design studies for the project, but Ares was ultimately cancelled in favour of solid-fuel ICBMs, which were safer to store and could be launched with much less notice.
Ares would also have been capable of placing a 4,000 kg payload into low Earth orbit as a single-stage to orbit launch vehicle.
The original article can be found at Ares (missile) and the edit history here.