RIP on linux

hello,
          I want to know does linux uses RIP? Where and in which
services? Does RIP is bound to Hardware Routers and not for linux set
as routers?
IS RIP the only protocol that sends routing update messages from one
Router to Other router?
          Does Routing protocols are Application or Network layer
protocols? If RIP can be implemented on linux then how the routing
messages sent? I read that RIP uses UDP? Is that right? What about
OSPF? 
 I am usinf Redhat 9.