Microsoft applications like "Word" or "Excel" let the user describe his document by properties like "title", "category" and so on. The application itself adds further information: last author, creation date etc. These properties are stored in so-called property set streams. A property set stream is a separate document within a POI filesystem. HPSF is POI's pure-Java implementation to read (and in future to write) property set streams.

Once the HPSF HOWTO is ready, it will describe what a Java application should do to read a property set using HPSF and retrieve the information it needs. Currently this is explained in the javadocs of the org.apache.poi.hpsf package only.

HPSF supports OLE2 property set streams in general, not only the special case of document properties mentioned above. The HPSF description describes the internal structure of property set streams.