PSPP is a program for statistical analysis of sampled data. It is a free replacement for the proprietary program SPSS.

PSPP supports T-tests, ANOVA and GLM analyses, factor analysis, non-parametric tests, linear and logistic regression, clustering, and other statistical features. PSPP produces statistical reports in plain text, PDF, PostScript, CSV, HTML, SVG, and OpenDocument formats. It can import data from OpenDocument, Gnumeric, text and SPSS formats.

PSPP has both text-based and graphical user interfaces. The PSPP user interface has been translated into a number of languages.

Instructions for PSPP installation are in INSTALL, including a list of prerequisite packages and other PSPP-specific information. Full documentation on PSPP's language is also included.

For information on differences from previous versions, please see file NEWS.

Source code for the latest release of PSPP is available at ftp://ftp.gnu.org/pub/gnu/pspp/. Test releases are at ftp://alpha.gnu.org/gnu/pspp/. Development sources are available at http://savannah.gnu.org/projects/pspp

The following miscellaneous notes apply to this release:

* On a few operating systems, such as OpenBSD, some of the
      tests may fail with messages similar to: 'Warning: cannot
      create a converter for "646" to "UTF-8"'.  These test
      failures may safely be ignored.

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, but we are happy to hear from users through any means.

The PSPP bug tracker and bug reporting mailing list are public. To privately report a security vulnerability in GNU PSPP, please send your report to the closed mailing list pspp-security@gnu.org. The PSPP developers will help you assess your report and fix problems prior to public disclosure.

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.

* 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.

* 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. It has not been tuned
      or extensively tested, however initial experience has given
      impressive results.

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.

For any copyright year range specified as YYYY-ZZZZ in this package note that the range specifies every single year in that closed interval.