PSPP is a program for statistical analysis of sampled data. It
interprets commands in the SPSS language and produces tabular output
in ASCII, PostScript, or HTML format.

PSPP development is ongoing. It already supports a large subset of
SPSS's transformation language.  Its statistical procedure support is
currently limited, but growing.

For information on differences from previous versions, please see file
NEWS.  Full documentation on PSPP's language can be found in the doc/
directory.
          
Source code for the latest release of PSPP is available at
ftp://ftp.gnu.org/pub/gnu/pspp/.  Older versions may be obtained from
ftp://alpha.gnu.org/gnu/pspp/.  Development sources are available from
CVS at http://savannah.gnu.org/projects/pspp
   
Questions and comments about using PSPP may be sent to pspp-users@gnu.org.
Bug reports may be filed at http://savannah.gnu.org/bugs/?group=pspp
or emailed to bug-gnu-pspp@gnu.org.  (We prefer the web-based system
because it makes it more difficult for us to lose track of bugs.)

The long term goals for PSPP are ambitious.  We wish to provide the
following support to users:

	* All of the SPSS transformation language.  PSPP already
          supports a large subset of it.

	* All the statistical procedures that someone is willing to
          implement, whether they exist in SPSS or not.  Currently,
          statistical support is limited, but growing.

	* Compatibility with SPSS syntax, including compatibility with
          known bugs and warts, where it makes sense.  We also provide
          an "enhanced" mode in certain cases where PSPP can output
          better results that may surprise SPSS users.

	* Friendly textual and graphical interfaces.  PSPP does not do
          a good job of this yet.

	* Attractive output, including graphs, in a variety of human-
          and machine-readable formats.  PSPP currently produces
          output in ASCII, PostScript, and HTML formats.  We will
          enhance PSPP's output formatting in the future.

	* Good documentation.  Currently the PSPP manual describes its
          language completely, but we would like to add information on
          how to select statistical procedures and interpret their
          results.

	* Efficient support for very large data sets.  For procedures
          where it is practical, we wish to efficiently support data
          sets many times larger than physical memory.  The framework
          for this feature is already in place, but it has not been
          tuned or extensively tested.

Over the long term, we also wish to provide support to developers who
wish to extend PSPP with new statistical procedures, by supplying the
following:

	* Easy-to-use support for parsing language syntax.  Currently,
          parsing is done by writing "recursive descent" code by hand,
          with some support for automated parsing of the most common
          constructs.  We wish to improve the situation by supplying a
          more complete and flexible parser generator.

	* Easy-to-use support for producing attractive output.
          Currently, output is done by writing code to explicitly fill
          in table cells with data.  We should be able to supply a
          more convenient interface that also allows for providing
          machine-readable output.

	* Eventually, a plug-in interface for procedures.  Over the
          short term, the interface between the PSPP core and
          statistical procedures is evolving quickly enough that a
          plug-in model does not make sense.  Over the long term, it
          may make sense to introduce plug-ins.