Page "Zero configuration networking" Paragraph 19

Service Location Protocol ( SLP ), the only protocol for service discovery to have reached the IETF Proposed Standard status, is supported by Hewlett-Packard's network printers, Novell, and Sun Microsystems, but ignored by some other large vendors.

SLP is described in RFC 2608 and RFC 3224 and implementations are available for both Solaris and Linux.