Also, Banyan continued to operate a closed OS. This required hardware manufacturers to submit hardware and driver requirements so that Banyan could write drivers for each peripheral. When more open systems with published APIs began to appear, Banyan did not alter their model. This made it difficult for client-side support to handle the explosive growth in, for example, printers. As competitors began to adopt some of VINES' outstanding wide area networking protocols and services, manufacturers were less inclined to send a unit to Banyan for VINES specific drivers when competitors let them write their own.