Rule based expert systems programmers experience similar difficulties in developing and maintaining large application programs: rules become instantiated when they shouldn't; the execution order of rules is undesirably nondeterministic, or worse, simply incorrect; and modifications to program behavior are difficult or unwieldy. All of these problems arise from the control strategies used by the development language, their implementation, and the programmers control over (and awareness of) them. This paper explores the impact of rule based program control on overall program modifiability. We present a language designed with efficiency, modifiability, and ease of use in mind. Throughout, we discuss traditional control strategies, improvements made through our research, and directions for futher study.