I do not know of such library myself but I guess it is solvable in other ways too. Like if you make a view in Lotus Notes with the data you need have it render as XML (Was a while since i worked in Lotus Notes but I guess you could make a page that renders the view in XML fashion or an agent that renders the data as XML or something). And then from the XML, import it to EPiServer via a plugin or maybe create a page provider if you don't need the data to be stored in EPiServer.

Ofc. its possible  to do similar stuff if you don't use XML as carrier, you can use comma separated text or whatever. or maybe make some service in Lotus Notes to communicate with via Soap or so (But I have never done such things so have no idea there) but you get the idea.