How are plug-in toolbars made?

[karayan]

I notice that many major sites (yahoo, ebay, etc.) offer g\free toolbars to their users. These toolbars seem to be imbedded into the browser's windows -- in some sort of plug-in fashion.

How are these toolbars developed? Language? Are there standards APIs used for IE and NS? Where do I get more info?

Thanks.

George

[winterflood_j]

no idea...
you could try asking yahoo.com or anyone else that has made one

jo