The purpose of this study was to investigate the longitudinal application of a suite of curriculum authoring tools (CATs) to inclusive classroom teaching practice in a secondary school setting. The study sought to establish whether the incorporation of the CATs into the teachers' curriculum development and implementation covaried with improved implementation integrity of classroom teaching practice over time. A repeated measures design was used to establish whether those teachers with high levels of tool use also recorded higher levels of implementation integrity in their use of specific inclusive teaching practices. The effects of the tools were measured using 578 50-minute classroom observations gathered over a 2.5-year period. The results indicated that higher levels of implementation integrity in classroom practice covaried with the extent to which the tools were used for the design and implementation of curriculum.