Collaborative editing (CE) has been an area of continuous research since early days of CSCW. Various CE systems have been studied in academia as research vehicles to investigate key technical issues in building advanced collaborative applications. In recent years, CE techniques have been increasingly adopted and further developed in industry for supporting real-world Internet or Cloud-based CE systems/services, such as Google Docs, Codoxware, IBM OpenCoWeb, Novell Vibe, and SubEthaEdit. This workshop aims to bring together CE academic researchers, industry developers, and end- users to discuss and exchange ideas on contemporary issues in researching, developing, and adopting CE systems. We have successfully organized this workshop annually at CSCW-related conferences. This year's workshop focuses on CE issues and techniques for supporting complex real-world documents (including but not limited to rich text, xml, spreadsheet, 2D/3D digital media, CAD, video, etc.), and evaluation of CE systems for such complex real-world documents.