In a model editing apparatus, a model transformation function transforms SM (source model) 0 into TM (target model) 0 , and generates TDM (transformation dependency model) 0 . Moreover, when an SM editor generates SM 1 by updating SM 0 , the model transformation function transforms SM 1 into TM 1 and generates TDM 1 . When a TM editor generates TM 0 _n by editing TM 0 independently of the change in SM 0 , a Change element registration function registers a difference Δ 2 between TM 0 and TM 0 _n in TDM 0 , thereby generating TDM 0 _n. Then, in response to a call, a merge function merges a difference Δ 1 between TDM 0 and TDM 1 extracted by a Δ1 extraction function, and a difference Δ 2 extracted from TDM 0 _n, according to prestored processing patterns.

Embodiments of the present invention address deficiencies of the art in respect to merging artifacts in a version control system and provide a novel and non-obvious method, system and computer program product for compositing deltas when merging artifacts in a version control system. In one embodiment, a method for compositing deltas for artifacts can be provided. The method can include generating deltas for a contributor artifact of an ancestor artifact, identifying interrelated ones of the deltas and grouping the interrelated ones of the deltas into a composited set of deltas. The method further can include rendering the composited set of deltas in a hierarchical view of a compare view for a version control data processing system in a development platform.