According to its proponents, open source style software development has the capacity to compete successfully, and perhaps in many cases displace, traditional commercial development methods. In order to begin investigating such claims, we examine the development process of a major open source application, the Apache web server. By using email archives of source code change history and problem reports we quantify aspects of developer participation, core team size, code ownership, productivity, defect density, and problem resolution interval for this OSS project. This analysis reveals a unique process, which performs well on important measures. We conclude that hybrid forms of development that borrow the most effective techniques from both the OSS and commercial worlds may lead to high performance software processes.

This study presents an initial set of findings from an empirical study of social processes, technical system configurations, organizational contexts, and interrelationships that give rise to open software. The focus is directed at understanding the requirements for open software development efforts, and how the development of these requirements differs from those traditional to software engineering and requirements engineering. Four open software development communities are described, examined, and compared to help discover what these differences may be. Eight kinds of software informalisms are found to play a critical role in the elicitation, analysis, specification, validation, and management of requirements for developing open software systems. Subsequently, understanding the roles these software informalisms take in a new formulation of the requirements development process for open source software is the focus of this study. This focus enables considering a reformulation of the requirements engineering process and its associated artifacts or (in)formalisms to better account for the requirements for developing open source software systems.

This paper develops an inductive theory of the open source software innovation process by focussing on the creation of Freenet, a project aimed at developing a decentralized and anonymous peer-to-peer electronic file sharing network. We are particularly interested in the strategies and processes by which new people join the existing community of software developers, and how they initially contribute code. Analyzing data from multiple sources on the Freenet software development process, we generate the constructs of "joining script",

Much recent research has pointed to the critical role of architecture in the development of a firm’s products, services and technical capabilities. A common theme in these studies is the notion that specific characteristics of a product’s design – for example, the degree of modularity it exhibits – can have a profound effect on among other things, its performance, the flexibility of the process used to produce it, the value captured by its producer, and the potential for value creation at the industry level. Unfortunately, this stream of work has been limited by the lack of appropriate tools, metrics and terminology for characterizing key attributes of a product’s architecture in a robust fashion. As a result, there is little empirical evidence that the constructs emerging in the literature have power in predicting the phenomena with which they are associated. This paper reports data from a research project which seeks to characterize the

The term Open Source is widely applied to describe some software development methodologies. This paper does not provide a judgment on the open source approach, but exposes the fact that simply stating that a project is open source does not provide a precise description of the approach used to support the project. By taking a multidisciplinary point of view, we propose a collection of characteristics that are common, as well as some that vary among open source projects. The set of open source characteristics we found can be used as a tick-list both for analysing and for setting up open source projects. Our tick-list also provides a starting point for understanding the many meanings of the term open source.

This study presents findings from empirical studies of software development practices, social processes, technical system configurations, organizational contexts, and interrelationships that give rise to free or open source 1 software (F/OSS) systems in different communities. F/OSS represents an approach for communities of like-minded

this report is supported by grants from the National Science Foundation #IIS-0083075, #ITR-0205679 and #ITR-0205724. No endorsement implied. Mark Ackerman at the University of Michigan Ann Arbor; Les Gasser at the University of Illinois, Urbana-Champaign; John Noll at the Santa Clara University; Chris Jensen, Mark Bergman, and Xiaobin Li at the UCI Institute for Software Research, and also Julia Watson at The Ohio State University are collaborators on the research project that produced this chapter. 1 1

The focus of this paper is to review what is known about free and open source software development (FOSSD) work practices, development processes, project and community dynamics, and other socio-technical relationships. It focuses on exploring how FOSS is developed and evolved based on an extensive review of a set of empirical studies of FOSSD projects that articulate different levels of analysis. These characterize what has been analyzed in FOSSD studies across levels that examine (i) why individuals participate; (ii) resources and capabilities supporting development activities; (iii) how cooperation, coordination, and control are realized in projects; (iv) alliance formation and inter-project social networking; (v) FOSS as a multi-project software ecosystem, and (vi) FOSS as a social movement. Next, there is a discussion of limitations and constraints in the FOSSD studies so far. Last, attention shifts to identifying emerging opportunities for future FOSSD studies that can give rise to the development of new software engineering tools or techniques, as well as to new empirical studies of software development.

In this paper, we present results from the study of a free software development virtual organization, the GNU Enterprise (GNUe) project, and how they develop software in a globally distributed free software development project. In particular, examples of how they mitigate and resolve conflict are presented. Conflict arises over the use of a non-free tool to create GNUe graphic, and over the use of a non-free tool for GNUe documentation. The GNUe developers resolve the conflict using internet relay chat (IRC), threaded email discussions, and community digests. We characterize the GNUe developers as an occupational subculture within the occupational community of free/open source software (F/OSS) developers and show how the beliefs in free software and freedom of choice, and values in cooperative work and community assist GNUe contributors in mitigating and resolving conflict. In addition, we show how, despite fluctuating boundaries of membership in a virtual organization, daily discussions on the GNUe IRC serve to build and perpetuate the global community of GNUe contributors as well as F/OSS developers in general.

Studying how a software system has evolved over time is difficult, time consuming, and costly; existing techniques are often limited in their applicability, are hard to extend, and provide little support for coping with architectural change. This paper introduces an approach to studying software evolution that integrates the use of metrics, software visualization, and origin analysis, which is a set of techniques for reasoning about structural and architectural change. Our approach incorporates data from various statistical and metrics tools, and provides a query engine as well as a web-based visualization and navigation interface. It aims to provide an extensible, integrated environment for aiding software maintainers in understanding the evolution of long-lived systems that have undergone significant architectural change. In this paper, we use the evolution of GCC as an example to demonstrate the uses of various functionalities of BEAGLE, a prototype implementation of the proposed environment.