This paper describes Window Strategies Environment (WSE), which is an environment for exploring different window strategies. It is a tool for developers who want to implement and explore different window strategies easily. WSE uses object oriented meth odology offering four hierarchical levels for customizing predefined window strategies. The highest level is a simple modifiable language for describing a few essential commands for each strategy. This kind of tool helps the developers to implement and test several approaches to window strategies before selecting one. Also it encourages the developer to direct some of the power to the user so that she can customize the user interface by selecting a preferred strategy from a predefined set of strategies. The environment is implemented under NeWS 1/1 [Sun87] window system for SUN 4/110. It uses Smalltalk style object oriented class mechanisms [Golberg83, Densmore] offered by NeWS but none of the original NeWS toolkits.