errr its free
Don't tell the dumbbois at CiscNo, but Jabber is open source protocol, they could have created their own client and integrated without capex.
Cisco Systems plans to assimilate the instant messaging software maker Jabber Inc. into the corporate collective, bolstering the network giant's arsenal of enterprise communication and collaboration tools against the likes of Microsoft, Google, IBM and others. Denver-based Jabber is the commercial software house behind the …
"The Jabber protocol acts as a bridge between the firm's own XML-based chat and proprietary Microsoft, AOL, and Yahoo IM clients "
No. There are plug-ins (oft 3. party) available for jabber servers (of which there are several flavours) referred to as gateways, which will bridge to other IM protocols (and other transports such as email).
There are _extensions_ to the core jabber protocol which define/advise on address translation (so for example fred@msn.com becomes fred%msn.com@msgateway.jabberhost.net ) and on service discovery of available gateways.
Bit more research needed, or least should have been better phrased IMO.