Software architecture in an open source world

“We do not appreciate being experimented on”: Developer and researcher views on the ethics of experiments on open-source projects

Do Open Source Developers Respond to Competition?: The (La)TeX Case Study

Many previous studies have shown that open-source technologies help democratize information and foster collaborations to enable addressing global physical and societal challenges. The outbreak of the novel coronavirus has imposed unprecedented challenges to human society. It affects every aspect of livelihood, including health, environment, transportation, and economy. Open-source technologies provide a new ray of hope to collaboratively tackle the pandemic. The role of open source is not limited to sharing a source code. Rather open-source projects can be adopted as a software development approach to encourage collaboration among researchers. Open collaboration creates a positive impact in society and helps combat the pandemic effectively. Open-source technology integrated with geospatial information allows decision-makers to make strategic and informed decisions. It also assists them in determining the type of intervention needed based on geospatial information. The novelty of this paper is to standardize the open-source workflow for spatiotemporal research. The highlights of the open-source workflow include sharing data, analytical tools, spatiotemporal applications, and results and formalizing open-source software development. The workflow includes (i) developing open-source spatiotemporal applications, (ii) opening and sharing the spatiotemporal resources, and (iii) replicating the research in a plug and play fashion. Open data, open analytical tools and source code, and publicly accessible results form the foundation for this workflow. This paper also presents a case study with the open-source spatiotemporal application development for air quality analysis in California, USA. In addition to the application development, we shared the spatiotemporal data, source code, and research findings through the GitHub repository.

Social Coding Sites (SCSs) are social media services for sharing software development projects on the Web, many open source projects are currently being developed on SCSs. Assessing the quality is a crucial element for better selection of a specific project serving people requirements or needs. In this paper, we reviewed existing traditional models which evolved prior the evolution of open source software as well as open source quality models. We evaluated the selected models according to their reflection with respect to social coding project success factors: sociality, popularity, activity and supportability. Eight models were included in our research as we only selected models that introduces explicit metrics well defined for measuring, neither a process nor a generic methodology. Based on our selection criteria, a summary of the findings we obtained is that existing models doesn’t fully consider or cover social factors for open source software evaluation hence there is a need for a model to measure the maturity / quality of open source projects from social factors perspective. We have also evaluated the existing models against a selected open source project hosted on social coding GitHub to assess each model applicability. Some of the measurements from the existing models were not applicable for evaluation.

Open Source developers play fundamental determinant role in the life of any open source project. This paper investigates developer motivation in contributing tirelessly to an open source project. Open source Onions were investigated and the developer layer modeled and validated based on ten case studies from SourceForge. Validation was based on Delphi's four rounds of successive stages. Results show that 62% of the developers around an open source development project community are skilled programmers, and that Open source developers are largely motivated by web based development platforms with universal programming language such as Java and that Developers are mostly attracted to the GPL licensed software development project with high project publicity as could be tracked from the hit rate on the project website. Finally, the few Core developers (Project Administrators) of about 19% actually controls and oversees the affairs carried out by about 81% of many developers showing the prominence of Pareto80/20 Principle in Open Source Project development.

In open source software development, a major challenge is the prioritization of new requirements as well as the identification of responsible developers for their implementation. Unlike conventional industrial software development, where requirements engineers have to explicitly define who implements what, in the context of open source development, developers (contributors) usually decide on their own which requirements to implement next. Contributors have to deal with a huge number of requirements where the recognition of the most relevant ones often becomes a crucial task with a high impact on the success of a software project. This fact defines our major motivation for the development of a prioritization tool for the ECLIPSE community which recommends relevant requirements (issues/bugs) to open source developers. Our tool uses real-world data from ECLIPSE in order to build a prediction model. We trained and tested our tool with different classifiers such as Naive Bayes (representing our baseline), Decision Tree, and Random Forest. The evaluation results indicate that the Random Forest classifier correctly predicts issues with a precision of 0.88 (F1-score 0.68).CCS CONCEPTS• Information systems → Recommender systems; • Humancentered computing → Open source software; • Computing methodologies → Machine learning approaches; Natural language processing; • Software and its engineering → Requirements analysis.

Open Source Software (OSS) is software products available to the public, with its source code to study, change, and improves its design. Open Source Software Development (OSSD) is the process by which open source software is developed within the confines of software engineering life-cycle methods. However when open source used for commercial purpose, then an open source license is required. Open source software is very often developed in a public and collaborative manner. The quality assurance principle under open source software development is an approach to improve software product quality against traditional methods and techniques. Despite the fact that the open source developments have seen remarkable successful in recent years, there are a number of product quality issues and challenges facing the open source development model. Many industries and business sectors are following or using OSSD, since they realize the benefits, but they do have some reservations concerning quality assurance in the form of program code quality, maintenance of the code and its quality, over the life-cycle of the product and third party usage. This paper reviews the literature of the process of the latest quality assurance, under open source software development methods and techniques. The result from this review is to show the process of quality assurance of open source software and that how it can affect the overall quality assurance principal.

Extensible Business Reporting Language (XBRL) is being adopted by European regulators as a data standard for the exchange of business information. This paper examines the approach of XBRL International (XII) to the meta-data standard's development and diffusion. We theorise the development of XBRL using concepts drawn from a model of successful open source projects. Comparison of the open source model to XBRL enables us to identify a number of interesting similarities and differences. In common with open source projects, the benefits and progress of XBRL have been overstated and ‘hyped’ by enthusiastic participants. While XBRL is an open data standard in terms of access to the equivalent of its ‘source code’ we find that the governance structure of the XBRL consortium is significantly different to a model open source approach. The barrier to participation that is created by requiring paid membership and a focus on transacting business at physical conferences and meetings is identified as particularly critical. Decisions about the technical structure of XBRL, the regulator-led pattern of adoption and the organisation of XII are discussed. Finally areas for future research are identified.

The plan to develop Evergreen, the open-source consortial library software, was announced in June 2004 by Lamar Veatch, state librarian and head of the Georgia Public Library Service (GPLS). Evergreen went live in 2006. That two-year period was filled with activity. It was a major decision by GPLS to develop new software of a scope never before attempted, but it was undertaken only after it had exhausted all other alternatives to run PINES, the resource-sharing public library consortium in Georgia. Evergreen was to be designed from the ground up as a new thing: a consortial library system, that is, an integrated library system for a large, geographically dispersed, resource-sharing consortium. Why did GPLS take this path and how did it go about doing it? The decision came about after a long chain of events made over many years in Georgia as it, like all states, wrestled with how best to provide public library services to its citizens. Policy decisions over many years followed a consistent direction. Local library organizational patterns commonly follow a model of treating each library separately resulting in what today are commonly called information silos, resulting in largely separate collections with weak communications among them. Resource sharing among the libraries in most state systems is through an interlibrary loan (ILL) process. Georgia, on the other hand, has consistently chosen another direction: joining the many small public libraries into larger resource-sharing regional libraries. Other states have worked on the idea, abandoned it, taken it up again and so on. It was an idea that the library community liked in theory, but before recent developments in computer technology, Georgia's path was unusual. The fundamental problem that all states must wrestle with in providing public library service - indeed for all entities providing any library service - is the great disparity of size, wealth and resources of the many libraries that exist. There are a few very rich libraries; however, most have only modest resources. Consider these figures from the latest national-level data we have for U.S. public libraries (FY 2005). Table 1 shows that the top quartile of these libraries by their total expenditures - that is, the 25% of public libraries that spent the most - spent $7.9 billion that year while the bottom three quartiles (the 75% that spent the least) spent $1 billion in total. Indeed, to press the point, the top 10% spent $6.5 billion. Think about that: Ten percent of the public libraries in the United States spent about 6.5 times as much money as the smallest 75% of the libraries. The big libraries are very big, and the small libraries are very small, and the disparities in expenditures that these figures demonstrate are consistent across other variables such as collections, resources and staff. Moreover, they are consistent with the pattern for other types of libraries. However, our story is centered on public libraries in the United States because of decisions made by GPLS. It is useful to note that the two largest open source library systems running in the United States, Evergreen and Koha, were developed for small public library settings. If you look at the expenditure figures above, it is not hard to imagine why - the large proprietary vendors prefer to concentrate their efforts where the money is. Within the open source framework, however, Evergreen and Koha have different approaches, with Evergreen being consortial for reasons that are discussed here. The disparities in resources outlined by the data present a profound information policy question for a consensual democracy: In a system of government that relies on an informed citizenry, are such disparities acceptable? Is it acceptable for the “haves” to have access to so much more information than the “have nots”? If not, how do we ameliorate the results of this disparity? Public library service as it is configured in the United States today developed before Google and other modern software developments that have relentlessly broken down information silos in other fields. Their configuration cannot adequately provide the vast pools of information and materials that are now available to the citizenry. One step in the right direction is consortial resource sharing, and another is to use these consortia to pool money to buy access to enhanced content for all the libraries in the consortium - especially those that could not otherwise have afforded this content - the “everything everywhere” library consortium. In its history (at least by the 1940s), Georgia decided to follow its subsequently consistent policy - with the normal stops and starts involved with politics - to bind the small public libraries in the state into larger, regional entities for resource sharing. That strategy was Georgia's way to get library resources to the “have nots.” The state provided both funding and direction toward that end. Although Georgia's largest libraries are typically independent, the smaller ones today are mostly in regional systems. In 1998, David Singleton, then at GPLS and now at Charlotte-Mecklenburg Public Library in Charlotte, North Carolina, suggested a universal borrower card for Georgia's public library users. Such a card would allow all citizens of Georgia to borrow an item from any library. Given both the amount of state funding and state strategic practices to group libraries into regions, such an idea was possible. Of course, the idea was not new to Georgia, but it fell on receptive Georgia soil since the infrastructure and the general acceptance of the idea of sharing resources were in place. Because of years of preparation, state guidance and vision, the idea would work. Y2K - the computer problem that existed because of the way computers handled dates - in the end was what led to the creation of PINES (the Georgia public library resource sharing network - the network of Georgia's regional library systems). Y2K money was allocated by the state, and an RFP for a statewide system was issued. One vendor's product stood out, and PINES was born in 1999 with Phase 1 linking 26 library systems with 90 outlets (central libraries, branches and bookmobiles). PINES was an immediate success. PINES users liked being able to borrow books from a larger set of libraries with a richer set of collections than one local library. They liked access to the longer tail, and PINES added more libraries and more users. Library users altered their behavior, and many bypassed their local libraries to have access to the larger, virtual collection. PINES grew until it started having problems with the underlying software that, famously, resulted in the system's production servers having to be rebooted during the middle of the day in order to be able to handle control of the transactions load. The software had reached a previously unknown limit. Given that the software that ran PINES is running other systems that have higher circulations and larger bibliographic databases than PINES, what limit had been reached? There were several, but the central one was the system could not keep up with the update load. The software was not designed for a consortium spread over a large area with updates such as checkouts, check-ins and cataloging changes to the central database coming from so many different places. In such a system, there are many people logged into the system changing the database at any one time, and the database, to be useful, has to be current. It should reflect what is checked in or out (transactions) and what the system owns (inventory) so that users searching will know if an item is available and librarians will know the state of items in the system. These functions are basic to a modern inventory control system. In PINES, there are thousands of terminals across the state logged into the database making changes, and each change has to be reflected in the database by “reindexing” it. While rebooting in this old system allowed the system to catch up with the changes, it could not be done frequently enough. The limit reached was a hard one, and there was no solution using that software. Meanwhile, more libraries wanted to join PINES. All the while, the circulation load was large and increasing. Any large piece of software has a design architecture: how it organizes its elements, what tools it uses, that is, how it does what it does. The design architecture, in turn, is a function of various factors, the two most important being system architecture and computer costs. Many old versions of old software still litter the ILS ecosystem. The software then running PINES began development in the era when mainframes ruled the earth. This legacy software has been adapted and changed and added to over the years. Elements had been bolted on and kludged, but, it is a fact that updating deployed software has proven to be an almost impossible task almost every time it has been tried. There are a thousand problems, and what most vendors of library software have done is start over using the more modern updated practices of the time. When the original PINES software was developed, computers were immensely expensive and software comparatively primitive. Better practices and more capable small computers existed when Evergreen was envisioned, and the developers used more modern software development processes to run on more capable computers that no longer cost a million dollars each to buy. An examination of alternatives in the market found none that had the capabilities necessary to run PINES then or in the future. What was Georgia to do? Limit PINES? Give up and abandon a policy direction it had followed so consistently and that had produced such benefits? Over software? After much discussion, GPLS embarked on a revolutionary path - an open source, consortial library system to run PINES. Work began on Evergreen mid-2004. The later a software system is developed, the more modern practices can be used in that development. Evergreen, for instance, was web-aware and used Unicode for text storage and representation from the beginning. To implement these capabilities, Evergreen did not require the costly and difficult rewrites to the foundational code necessary for ILSs that had their basic code written before Unicode had been developed. Unicode is important because it allows a system to handle non-Roman scripts, including characters in Chinese and Arabic. Evergreen's development began with practices then in place in the business world. These practices today result in software that is modular, scalable and relatively easy to update - at least compared to legacy software that is even as little as five years old. Evergreen uses a service-oriented architecture (SOA) with representational state transfer (REST) and “n-tier” architectural design concepts. Let us explore these concepts a bit. The development philosophy behind these elements is that software is based on distributed services that communicate and collaborate through a set of standards, that is, it should be “service oriented.” In Evergreen, the open scalable request framework (OpenSRF, pronounced “open surf”) is such an SOA framework. OpenSRF is, in many ways, the key to Evergreen because it does so many things. OpenSRF provides load balancing and is robust and scalable. It also allows the development of software without requiring a detailed knowledge of Evergreen's structure. In effect, the Evergreen layer consists of a number of applications each of which rides on top of OpenSRF. The result is that the developer need only know the APIs and what information the program elements require and what they will reply to write new capabilities into Evergreen. OpenSRF handles the details of implementing a stateful, decentralized service architecture while the Evergreen code supplies the interface and business logic. OpenSRF is now a separate open source project. Networking follows a design philosophy that is often introduced to students with the OSI Reference Model. The model describes seven layers that pass information among each other to provide network services in a manner similar to what one finds with SOA. “N-tier” application architecture is a related idea where the tiers communicate and collaborate with each other by established standards. We see these operations in our daily lives. If, for example, a new version of Firefox comes out, we can change the old version for the new one without changing the operating system or reformatting our hard drives. We usually do not even have to reboot. Why? Because of the underlying architecture where each program communicates with the other parts of the network software by established rules - application programming interfaces (APIs) - that specify how the various elements involved exchange needed information. So, to change a part or one tier does not require a massive rewrite of the entire code, just what needs to be adjusted. As mentioned, the Evergreen middle layer rides on top of OpenSRF, and the user interfaces (the OPAC and staff client) ride on top of Evergreen. In short, REST is a set of principles that establishes an architectural style for large, scalable applications. Evergreen also uses other open source projects - there are no proprietary pieces in Evergreen - to supply needed functionality. One advantage of open source applications is that a developer working on one project can use what is already tested and proven by other projects. PostgreSQL (“Postgres”) is an enterprise-grade relational database system with over 15 years of development. It was chosen for Evergreen because it was virtually the only open source database system that had the capabilities to support a system with the database structure and the transactions load the size of PINES. Another key application is XUL (pronounced “zool”) which stands for XML user interface language. Developed by the Mozilla project, XUL allows fully featured cross-platform web applications. Perhaps the best known XUL-driven application is the Firefox web browser. There are, as you see, a number of pieces to the Evergreen puzzle. These modules work together, and each can be changed when necessary without affecting the others as long as the changes do not affect the communications among them. Using these practices, coupled with the open source framework, provided a flexible method for very rapid development of Evergreen in the early days and continues to this day. Focus groups were formed to ask library staff and patrons what features they would like to see and how they would like the OPAC to perform. How well they did that job is indicated by the increased usage that followed the introduction of Evergreen. For instance, year-over-year, holds increased by 30% - same libraries, same network, but a new interface that users found easier to use, and they did. The general process for development was “release early, release often,” a process followed to this day. Small, iterative changes were made and released for comment and testing - not rare mega updates. If there were a problem, the software could be fixed relatively quickly. In addition, the software was open source so that it was developed in the open, not secretly by a small group. Many eyes looking at software makes better code. Another aspect of Evergreen's development is “scratching an itch.” That is, development tends to focus on the problems that people want fixed, not necessarily theoretical problems or capabilities dreamt up by product managers in response to real or imagined competitive pressures. Any kind of software development will have its strengths and weaknesses. Scratching an itch will solve problems people really have, but the community does need a mechanism to guide development strategically to make sure that while solving this or that problem the software stays a coherent whole. As a result of what was learned about the first iteration of PINES, there were several key results expected from Evergreen. The original charge was to build something “scalable, robust and fault-tolerant.” And, of course, open source. What do those three new terms mean? Scalable means that the software can be deployed in different-sized libraries and that adding capacity is relatively easy. At the point where the decision was being made to move from the proprietary system that ran PINES, the server upgrade for the old system would have cost $1.5 million for a large server. Evergreen development cost the GPLS much less than that. Learning that lesson, Evergreen can be upgraded by adding “commodity” servers - that is, servers from any manufacturer or any do-it-yourself builder, and they can be added as needed. OpenSRF, clearly, allows Evergreen to scale easily. Because Evergreen is easy to use - remember the focus groups - as a library's users learn the software, they use it more, and growth can be done by adding relatively cheap, redundant servers, not million dollar boxes running proprietary software. Add a server or two, load OpenSRF, and you have upgraded. Evergreen runs on laptops, is currently running on a home library, and runs PINES with 16 million circulation transactions. Robust. Evergreen was designed to be able to keep functioning in dire circumstances. When a backhoe severed the PINES network, the Evergreen staff clients allowed libraries that were disconnected from the central databases to continue checking out books. When the network was restored, the database was updated by an established procedure. There was no need to write down transactions on paper. Consider: PINES has had a number of days recently with 100,000 circulations. If half the network were down for a half a day, that could be 25,000 sheets of paper to be managed. Not with Evergreen. Fault-tolerant. Servers can fail, and the system will keep on functioning. The use of redundant servers allows one to fail and the others to keep on functioning. Evergreen was designed as much as possible to never go down. Reflecting its history, Evergreen does not have acquisitions nor serials modules. Work on these two services is ongoing with releases expected by Spring 2009. It is a development project, but one coming from the library world to solve library problems. As was observed above, it has been quite difficult in the past to update software to reflect new demands on it. It did prove relatively easy to add web awareness to most existing library software but rather more difficult to add Web 2.0 capabilities and Unicode. Consortial capabilities have proved daunting. And as a result of Evergreen such capabilities are now touted by software in the market that may soon have those capabilities, too. How does Evergreen avoid these kinds of pitfalls of obsolescence? Maybe it doesn't but Evergreen's practices reflect the current best guess about how to engineer software so updating it is never as painful as it has been in the past with code bases even a few years old. Welcome to the future, version 1.

The popularity of open source has witnessed significant growth in the past two decades. The sustainability and success of open source projects rely heavily on the active community of contributors, who have the freedom to join or depart voluntarily. The churn of core developers can have detrimental effects on the continuous development and progress of these communities. Therefore, previous studies have aimed to identify the factors that influence developer churn and reveal its impact on open source communities. However, there is currently a lack of research on predicting whether a developer will leave or retain within a given timeframe. This article aims to bridge this gap by introducing a novel model called context-aware dynamic graph neural network (ConDyGNN), which is designed specifically for predicting developer churn in open source communities. By leveraging historical data, this model takes into consideration various factors such as developers’ activities, collaborative networks, and community context information. To capture both temporal dependencies and spatial correlations among different developers, temporal convolutional network (TCN) and graph convolutional network (GCN) modules are employed in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ConDyGNN</i>. Furthermore, a context-aware module based on a multihead attention mechanism is proposed to effectively integrate macrolevel community information and enhance the predictive performance. The superiority of the proposed model is empirically demonstrated through extensive comparative experiments and an ablation study.

Robustness of the collaborative knowledge network (CKN) is critical to the success of open source projects. To study this robustness more comprehensively and accurately, we constructed a weighted CKN based on the semantic analysis of collaborative behavior, where (a) open source designers were the network nodes, (b) collaborative behavior among designers was the edges, and (c) collaborative text content intensity and collaborative frequency intensity were the edge weights. To study the robustness from a dynamic viewpoint, we constructed three CKNs from different stages of the project life cycle: the start-up, growth and maturation stages. The connectivity and collaboration efficiency of the weighted network were then used as robustness evaluation indexes. Further, we designed four edge failure modes based on the behavioral characteristics of open source designers. Finally, we carried out dynamic robustness analysis experiments based on the empirical data of a Local Motors open source car design project. Our results showed that the CKN performed differently at different stages of the project life cycle, and our specific findings could help community managers of open source projects to formulate different network protection strategies at different stages of their projects.

The success of software projects has many different facets: meeting user requirements, being developed within given budget and time constraints, and actually being used. We focus on one of them: the pattern of adoption by users, and its possible relationship with continued development. This is done based on readily available data for open source projects, namely their releases and downloads. Rather than just classifying projects as "successful" or "failure", we identify six distinct patterns of how the download rate changes with time that illuminate different aspects of successful or failed projects. "You're not thinking fourth dimensionally!" Dr. Emmett "Doc" Brown, Back To The Future III, scene 8

Background: The popularity of the open source software development in the last decade, has brought about an increased interest from the industry on how to use open source components, participate in the open source community, build business models around this type of software development, and learn more about open source development methodologies. Aim: The aim of this study is to review research carried out on usage of open source components and development methodologies by the industry, as well as companies’ participation in the open source community. Method: Systematic review through searches in library databases and manual identification of articles from the open source conference. Results: 19 articles were identified. Conclusions: The articles could be divided into four categories: open source as part of component based software engineering, business models with open source in commercial organization, company participation in open source development communities, and usage of open source processes within a company.

By reviewing the history of the open-source movement and highlighting recent research on its unique developmental processes, the author suggests that there are general lessons for anyone seeking to encourage innovation in any field or industry. What incentives, for instance, spark these Internet-based communities of software developers to innovate voluntarily outside the company's boundaries without formal work agreements? Research shows that open-source software developers freely reveal and share information because they garner personal benefits, such as reputation enhancement, expertise refinement and, quite simply, enjoyment. Researchers also note that, since most of these benefits are contingent upon membership in well-functioning developer enclaves, a sense of community is important to the open-source phenomenon. For example, identification with the highly esteemed Linux operating-system project instills a sense of responsibility and loyalty among contributors, who are motivated by their perceived indispensability to the team. Researchers point out, however, that developers also are motivated by a pragmatic desire to customize software. Much of the referenced research explores the unusual nature of open-source licensing agreements and intellectual-property protection. That is, open-source licenses guarantee the rights not of developers, but of future users against appropriation, and developers guard their work zealously with online sanctioning, brands and logos. Noting that the products emanating from open-source projects are often commercially attractive and widely used in business and government (for example, at IBM, NASA, Sun Microsystems, the German government), the author concludes by discussing the implications for future business activities.

There has been a recent surge of interest in open source software development, which involves developers at many different locations and organizations sharing code to develop and refine programs. To an economist, the behavior of individual programmers and commercial companies engaged in open source projects is initially startling. This paper makes a preliminary exploration of the economics of open source software. We highlight the extent to which labor economics, especially the literature on career concerns’, can explain many of these projects’ features. Aspects of the future of open source development process, however, remain somewhat difficult to predict with off-the-shelf’ economic models.