  The tractability of the lightweight description logic EL has allowed for the
construction of large and widely used ontologies that support semantic
interoperability. However, comprehensive domains with a broad user base are
often at odds with strong axiomatisations otherwise useful for inferencing,
since these are usually context-dependent and subject to diverging
perspectives. In this paper we introduce Standpoint EL, a multi-modal extension
of EL that allows for the integrated representation of domain knowledge
relative to diverse, possibly conflicting standpoints (or contexts), which can
be hierarchically organised and put in relation to each other. We establish
that Standpoint EL still exhibits EL's favourable PTime standard reasoning,
whereas introducing additional features like empty standpoints, rigid roles,
and nominals makes standard reasoning tasks intractable.
