Spline is a new-age 3D modeling/animation software designed for the web. The company upgraded its domain name from Spline.design to the EBM (Exact Brand Match) Spline.com in April 2021.
Spine also said that it has acquired the domain Spline.pizza (just in case!) and Spline.so. By securing their ideal domain, this company owns its brand completely, so why not play with other extensions as well?