Acknowledgments
This review is in part stimulated by ongoing discussions and collaborative activities amongst a diverse group of scholars communicating as part of the Re-generating CHAT research network, www.re-generatingchat.com. I give thanks to my colleague Ben Kirshner for critical feedback on the substance of this review. I am also grateful to Antti Rajala, Beth Fernholt and the rest of the editorial staff of Mind, Culture, and Activity for their invaluable comments, which contributed to the materialization of this review.