Cerberus Project is a sculpting team (often abbreviated CP). They sculpted the Delf line that was sold through Luts, as well as the MiniFee line that was first sold through Luts, and is now sold through Fairyland.
Currently, Cerberus Project releases dolls through Fairyland, and has revoked the Luts release of their Delf sculpts. Luts owns the trademarked name "Delf," which is why the Fairyland Cerberus Project releases have names relating to "Fee," and the Luts releases unrelated to Cerberus Project (Junior Delf, Senior Delf, etc.) have names relating to "Delf."