PC-ORD performs multivariate analysis of ecological data entered in spreadsheets. The emphasis is on nonparametric tools, graphical representation, randomization tests, and bootstrapped confidence intervals for analysis of community data. In addition to utilities for transforming data and managing files, PC-ORD offers many ordination and classification techniques not available in major statistical packages including: CCA, DCA, Indicator Species Analysis, Mantel tests and partial Mantel tests, MRPP, PCoA, perMANOVA, RDA, two-way clustering, TWINSPAN, Beals smoothing, diversity indices, species lists, many ordination overlay methods (quantitative, symbol-coding, color-coding, grid, joint plot, biplot, successional vector), various rotation methods, 3-D ordination graphics, Bray-Curtis ordination, city-block distance measures, species-area curves, tree data summaries, publication-quality dendrograms, autopilot mode nonmetric multidimensional scaling (NMS or NMDS).