Abstract
User satisfaction has always been a major factor in the success of software, regardless of whether it is closed proprietary or open source software (OSS). In open source projects, usability aspects cannot be improved unless there are ways to test and measure them. Hence, the increasing popularity of open source projects among novice and non-technical users necessitates a usability evaluation methodology. Consequently, this paper presents a usability maturity model specifically aimed at usability-related issues for open source projects. In particular, the model examines the degree of coordination between open source projects and their usability aspects. The measuring instrument of the model contains factors that have been selected from four of our empirical studies, which examine the perspectives of OSS users, developers, contributors and the industry. In addition to presenting the usability maturity model, this paper discusses assessment questionnaires, a rating methodology and two case studies. (C) 2012 Elsevier Ltd. All rights reserved.