[kagebe]

Linear types are a more fundamental concept (in functional programming and type theory) than reference capabilities, since they apply to values of any type and a linear type system does not need any references or objects that have state and behaviour.

The "linearity" of linear types comes from the typing rules of values with a linear type: They must be used exactly once. In fact, the simple typing rules of a linear type system allows one to implement all manner of capabilities and especially capabilities for references.