TitanIM obtained a commercial license with paid support, which does not come cheaply but allows them to use the engine early for special simulators. Right now the only way to use the engine is with our direct participation, since it's still lacking a lot of stuff and our participation is needed to implement various features and process the data used by the engine etc.
You can buy a WIP version of Anteworld, a sandbox game built on top of the evolving OT engine. It may eventually become a full "released" game, but since it serves as a tech demo of the engine, it may be never really finished.
It's aimed at people who want to experience how the tech works, with ability to create vehicle mods and limited non-commercial game play mods.
For commercial use you basically have to be a company with proven track record and sufficient funding allocated for the project. The engine may be released in the future, but likely only after we release other game(s) on it and make it a fully usable engine in the process.