From their website:
Funded on Kickstarter in February 2014, Hero Forge is a platform which allows user to create detailed characters in 3D with an easy-to-use character customizer, then get them 3D printed and shipped to your doorstep! Designed with the tabletop gamer in mind, Hero Forge lets you print figures in classic tabletop miniature scale (28mm-30mm), 3" scale statuettes (2x size), or 6" scale statuettes (4x size).
3D printing and shipping is done through our partners at Shapeways, one of the leading names in the commercial 3D printing industry. This means we can grow and change as the industry does, adding new 3D printed materials, new features, and new manufacturing methods as they hit the scene.
Gone are the days of rooting through poorly stocked shelves or browsing low-rez image galleries for something that vaguely resembles your hero: design your character from the ground up and see it in full 3D, and finally have a miniature that captures your vision.