In this paper we discuss the management of semi-structured data, i.e., data 
that has irregular or dynamically changing structure.  We describe components 
of the Stanford TSIMMIS Project that help extract semi-structured data from
Web pages, that allow the storage and querying of semi-structured data,
and that allow its browsing through the World Wide Web.  A prototype
implementation of the {\sc Tsimmis} system as described here is currently
installed and running in the database group testbed.