It certainly is good to see indeterminate is supported in the core (unlike JCheckBox). But coming from a business model background I see the need to write a wrapper on top of it, because in the business model the indeterminate state is not something separate from the actual value; a boolean itself can have three values: true, false and null. So binding the checkbox to a business model directly is not possible with the current implementation in JFX; we need to introduce a virtual Boolean (capital is intentional) property that deligates to selected and indeterminate.