Windows CalDAV client for Zulu/Subscribe

Which CalDAV clients would people recommend for communicating with read only Calendars produced by Zulu (& SeedCode Subscribe)?
So far I'm not having luck with Sunbird, which seem to want me to create an account, rather than insert just a URL.
So far I'm not having luck with Sunbird, which seem to want me to create an account, rather than insert just a URL.