They are very common for software and complete systems including serious amounts of custom software. Also partners on IDIQs, especially large multi-award ones,

They are very common for software and complete systems including serious amounts of custom software. Also partners on IDIQs, especially large multi-award ones, are very common. At least they are on the civilian side. About half my life is spent working on proposals in response to tasks for complete systems issued under multi-award IDIQs.