This list of 20 free statistical software packages is divided into general purpose and vertical application lists.
AdaMSoft is a data mining package with support for data management and hundreds of statistical functions.
Dap supports data management, analysis and data visualization. Performs calculation of means, percentiles, correlation, ANOVA, linear and logistic regression and non parametric statistics. Command line interface.
Develve – statistical analysis software supporting wide variety of tests in a science and R&D environment.
GNU Data Language – free alternative to IDL, providing data analysis and visualization functionality.
MacAnova – strengths are analysis of variance and related models, matrix algebra, time series analysis and multi-variate exploratory statistics. Windows, Mac and Unix
Octave is a general purpose mathematics language with statistical functions. Similar to the paid for Matlab.
OpenMx – a package for R allows estimation of a wide variety of advanced multivariate statistical models.
PSPP – yes it’s a pun on SPSS (IBM’s analytics platform) and looks pretty much the same as SPSS. Many statistical procedures and functions supported.
R – the most widely used statistics and data analysis program. Steep learning curve, but almost anything can be done in R.
Salstat – often used for analysis of scientific data.
SCaViS – statistical analysis framework for scientific computation, data analysis and visualization.
Scilab – for numerical computation in engineering and scientific applications. Provides many tools for data analysis and modeling.
Simfit – supports simulation, curve fitting, statistics and graph plotting.
SOFA Statistics – statistical analysis and reporting package with very nice graphics.
Statistician – free lite version supporting hundreds of statistical functions within Excel.
Statistical Lab – explorative and interactive tool with graphical interface and support for many statistical functions.
WinBugs – Bayesian statistical analysis program using Markov Chain Monte Carlo (MCMC) methods.
CSPro – Census and Survey Processing System, used for entering, editing, tabulating, mapping and disseminating census and survey data.
Dashboard of Sustainability – models complex relationships among economic, social and environmental variables.
Epi Info – for epidemiology, supporting electronic survey creation, data entry and analysis.
Gretl – Gnu Regression, Econometrics and Time-series Library. Many estimators – least squares, maximum likelihood, GMM. ARIMA, GARCH, VARs and VECMs supported.
WinPepi – statistical analysis program for epidemiologists with over 100 modules.