This editor "was designed to enable scholars working on a critical edition or on a text with commentary or translation to prepare a camera-ready copy or electronic publication without bothering much about making up and page proofs. Its features ... meet the practical needs of the scholar ... The possibility to search for and visualise manuscript constellations may be of considerable help in detecting affiliations between sources. It is the primary purpose of the Classical Text Editor to do the automatable work which consumes so much time and energy, and let the scholar concentrate on scientific issues."
It's a program I might actually use, even though I find that ConnectedText works very well for the first stages of writing a commentary.