Saints Row: The Third modders have had to rely on community-created tools to make Volition's game even more lively. Jeff Thompson, Volition's studio director of programming, is currently preparing official engine tools to share with the mod community, prominent modder IdolNinja explains in a blog post.
In addition to Saints Row: The Third documentation, Thompson is preparing official Saints Row 2 tools – something IdolNinja explains is a "test run" for Saints Row 4. "In simple terms, the modding community will finally be able to create and offer new clothing, new vehicles, new guns, new NPCs, new missions, and even new world geometry which will greatly extend the life of the series and enhance the Saints Row games in ways we never even dared to dream of," IdolNinja explains.
IdolNinja concludes that Thompson is expected to send something along this week, though there's no indication if that'll be the Volition mod tools or just the first steps in making that happen.