Authoring tools for Intelligent Tutoring System (ITS) have been shown to decrease the amount of time that it takes to develop an ITS. However, most of these tools currently do not extend to collaborative ITSs. In this paper, we illustrate an extension to the Cognitive Tutor Authoring Tools (CTAT) to allow for development of collaborative ITSs that can support a range of collaboration scripts. Authoring tools for collaborative ITSs must be flexible enough to allow for different learning goals and different collaboration scripts. We discuss how two collaboration scripts that we are using in our research on fractions learning are implemented in CTAT. The examples illustrate how CTAT flexibly supports collaborative tutors by running synchronized tutor engines for each student, and how it supports the development of collaborative tutors through the use of multiple behavior graphs that use no programming to develop. [This paper was published in: "Proceedings of the Workshops at the 16th International Conference on Artificial Intelligence in Education AIED 2013 Memphis, USA, July 9-13, 2013," Vol. 1009, edited by Erin Walker and Chee-Kit Looi, CEUR-WS.org, 2013, pp. 1-10.]