Transforming Google CSEs into OpenSearch descriptions is simple, even when Firefox needs some proprietary <moz:SearchForm> magic to get it right.
For older browsers not supporting OpenSearch each CSE has its own default gadget for uses on iGoogle, blogger, and elsewhere. I created a smaller configurable tiny CSE variant, to use it edit the cx-number, e.g., 001904119753490578822%25:zvsejdqm-pw for the xyzzy-CSE.
CSEs hosted by Google have one issue, creators cannot easily publish the source for users wanting to know what the CSE really does. Here's a snapshot of the sites currently covered by the xyzzy-CSE:
alvestrand.no, arkko.com, ecma-international.org, gmane.org/gmane.ietf.* (ditto org.w3c.*), iab.org, iana.org, icann.org, icir.org, iesg.org, ietf.org (excl. lists), imc.org, irtf.org, isc.org, isi.edu, isoc.org, itscj.ipsj.or.jp/ISO-IR, jabber.org, langtag.net, omniplex.blogspot.com (this blog), openspf.org, postel.org, rfc-editor.org, rfc-ignorant.org, rsa.com/rsalabs, standardstrack.com, unicode.org, w3.org, xml.resource.org, xmpp.org, and my own xyzzy mirrors (plus googlets).
