SpaceStat provides tools for the creation of spatial weights matrices, exploratory spatial data analysis, and spatial econometric analyses/spatial regression. The functionality of SpaceStat is complemented by the SpaceStat Extension for ArcView.
SpaceStat is organized into four modules, each concerned with a specific set of functionality:

Data Module: data input, manipulation and transformation
Tools Module: spatial weights creation, manipulation and analysis
Explore Module: descriptive spatial statistics
Regress Module: spatial regression analysis
The SpaceStat Extension adds two menu items to the View GUI in ArcView, Data and SpaceStat:

The Data menu item is also available in the Table GUI. The functionality of the two menus is as follows:
Data Menu: data interchange between ArcView and SpaceStat
SpaceStat Menu: visualization of SpaceStat data analysis results