Data analysis >> Statistical analysis

Analyse-It: "Powerful and accurate statistical analysis and charting add-in software for Microsoft Excel." (Commercial, Windows)

DataDesk: "brings fast, easy-to-use visual analysis to your desktop. It provides interactive graphical tools for exploring and understanding your data—for finding the patterns, relationships, and exceptions." (Commercial, multi-platform)

DataLight: "An easy-to-use statistical analysis application. For the novice and expert user. Runs inside your web browser." (Commercial, web-based)

Dataplot: "a free, public-domain, multi-platform (Unix, VMS, Linux, Windows 95/98/ME/XP/NT/2000, etc.) software system for scientific visualization, statistical analysis, and non-linear modeling. The target Dataplot user is the researcher and analyst engaged in the characterization, modeling, visualization, analysis, monitoring, and optimization of scientific and engineering processes." (Free, multi-platform)

Insightful Miner: "a powerful, scalable, data mining and analysis workbench that enables organizations to deliver customized predictive intelligence where and how it is needed. Its easy-to-use interface is specifically designed for statisticians and business analysts without specialized programming skills" (Commercial, Windows)

MATLAB®: "supports the entire data analysis process, from acquiring data from external devices and databases to producing presentation-quality output" (Commercial, Windows/Mac/Linux/Solaris)

MicrOsiris: "a comprehensive statistical and data management package for Windows developed and freely distributed by Van Eck Computer Consulting. It is derived from OSIRIS IV, a statistical and data management package developed and used at the University of Michigan and includes special techniques for data mining and analysis of nominal- and ordinal-scaled data (MNA, MCA)." (Free, Windows)

Minitab 15: "gives you the statistical tools you need to analyze your data and improve quality in one easy-to-use package. It is the leading software used to implement Six Sigma worldwide." (Commercial, Windows)

Open Epi (Open Source Epidemiologic Statistics for Public Health): "provides statistics for counts and measurements in descriptive and analytic studies, stratified analysis with exact confidence limits, matched pair and person-time analysis, sample size and power calculations, random numbers, sensitivity, specificity and other evaluation statistics, R x C tables, chi-square for dose-response, and links to other useful sites." (Open source, multi-platform)

R: "language and environment for statistical computing and graphics"; powerful data mining tool; produces high quality graphs. R/tm, text mining package for R, was recently released: "[P]rovides a wide variety of statistical (linear and nonlinear modelling, classical statistical tests, time-series analysis, classification, clustering, ...) and graphical techniques, and is highly extensible."  (Free; open source, multi-platform; via NY Times/ Matt Jockers)

Rwui: "creates web applications for you for running R scripts" (Free, web-based)

Sample Size Calculator: simple online tool for calculating sample size according to different variables (Free, web-based)

SAS Analytics: "provides an integrated environment for predictive analytics and descriptive modeling, data mining, text mining, forecasting, optimization, simulation, experimental design and more" (Commercial, Windows)

SPSS: "a statistical and data management package for analysts and researchers. SPSS and most of its add-on modules run on the most popular operating platforms: Windows®, Mac®, and Linux®." (Commercial, multi-platform)

StatCrunch: web-based statistical analysis & data-sharing, "allows users to share data sets, results and reports...items are also cross referenced" (Commercial, available only through Pearson education; web-based)

Statistical Lab: "an explorative and interactive tool designed both to support education in statistics and provide a tool for the simulation and solution of statistical problems." (Free, GPL)

VassarStats: "useful and user-friendly tool for performing statistical computation" (Free, web-based)