OrbisGIS allows you to load Web Map Service (WMS).
Due to the OpenGIS, "Web Map Service Interface Standard (WMS) provides a simple HTTP interface for requesting geo-registered map images from one or more distributed geospatial databases. A WMS request defines the geographic layer(s) and area of interest to be processed. The response to the request is one or more geo-registered map images (returned as JPEG, PNG, etc) that can be displayed in a browser application. The interface also supports the ability to specify whether the returned images should be transparent so that layers from multiple servers can be combined or not." (http://www.opengeospatial.org/standards/wms)
Suite : Open a WMS
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