I am preparing for a one hour webinar on Open Source ILS Add-on products. By "ILS Add-on," I mean products that extend the functionality of the ILS and wish seem to fall into three main categories: discovery interface, and metasearch.

If you are using, have used or have knowledge of any of the following products, I'd be much obliged if you'd tell me a bit about your experience. Like it?  Love it? Using it?  Know it is dead?  Know something better?  You know it works with Koha/Evergreen/anything else?

Thanks in advance!

Discovery Interface products:
SOPAC2
Blacklight
Kochief
Scriblio
VuFind
XC

Metasearch:
LibraryFind
Pazpar2
dbWiz

ILL:
Relais (not quote OSS yet?)
PLEIAS