Orcus is a library that provides a collection of standalone file
processing filters. It is currently focused on providing filters
for spreadsheet documents, but filters for other productivity
application types (such as wordprocessor and presentation) are
in consideration.

The library currently includes the following import filters:

    Microsoft Excel 2007 XML
    Microsoft Excel 2003 XML
    Open Document Spreadsheet
    Plain Text
    Gnumeric XML
    Generic XML

The library also includes low-level parsers for the following:

    CSV
    CSS
    XML
    JSON

These parsers are all implemented as C++ templates and require a
handler class passed as a template argument so that the handler class
receives various callbacks from the parser as the file is being parsed.