Get it here: https://github.com/jjmccollum/open-cbgm
From the readme:
The Coherence-Based Genealogical Method (CBGM) is a novel approach to textual criticism, popularized by the Institut für Neutestamentliche Textforschung (INTF) for its use in the production of the Editio Critica Maior (ECM) of the New Testament. It is a meta-method, combining methodology-dependent philological decisions from the user with efficient computer-based calculations to highlight genealogical relationships between different stages of the text. To establish genealogical relationships in the presence of contamination (understood to be a problem in the textual tradition of the New Testament), the CBGM makes a number of philosophical and methodological innovations, such as the abstracting of texts away from the manuscripts that preserve them (and the resulting rejection of hypothetical ancestors as used in traditional stemmata), the encoding of the textual critic’s decisions in local stemmata of variants, and the use of coherence in textual flow to evaluate hypotheses about the priority of variant readings.