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. Instructions for installation are in INSTALL. Before you install PSPP, you will need to install certain prerequisites: * An ANSI C compiler and tool chain. * GNU make. Other make programs will not work. * The GNU Scientific Library (libgsl), version 1.6 or later, including libgslcblas included with GSL. * Perl, version 5.005_03 or later. (Perl is required during build but not after installation.) * Optional: libncurses. Without it, PSPP will assume it is running in an 80x25 terminal. * Optional: libreadline and libhistory. Without them, interactive command editing and history features will be disabled. * Optional: libplot (from GNU plotutils). Without it, graphing features will not work. If you do not have it installed, you must run `configure' with --without-libplot. * Optional: GTK+ version 2.6.0 or later, plus libglade 2.0 or later. Without them, the GUI will not be built. If you do not have these installed, you must run `configure' with --without-gui. 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.