Summary Scholars worldwide leverage science gateways/virtual research environments (VREs) for a wide variety of research and education endeavors spanning diverse scientific fields. Evaluating the value of a given science gateway/VRE to its constituent community is critical in obtaining the financial and human resources necessary to sustain operations and increase adoption in the user community. In this article, we feature a variety of exemplar science gateways/VREs and detail how they define impact in terms of, for example, their purpose, operation principles, and size of user base. Further, the exemplars recognize that their science gateways/VREs will continuously evolve with technological advancements and standards in cloud computing platforms, web service architectures, data management tools and cybersecurity. Correspondingly, we present a number of technology advances that could be incorporated in next‐generation science gateways/VREs to enhance their scope and scale of their operations for greater success/impact. The exemplars are selected from owners of science gateways in the Science Gateways Community Institute (SGCI) clientele in the United States, and from the owners of VREs in the International Virtual Research Environment Interest Group (VRE‐IG) of the Research Data Alliance. Thus, community‐driven best practices and technology advances are compiled from diverse expert groups with an international perspective to envisage futuristic science gateway/VRE innovations.

Gateway workshops have been held on multiple continents in 2015, with the International Workshop on Science Gateways held in Budapest in June 2015 and the recent Australasian installation in October.This special issue represents contributions from the tenth Gateway Computing Environments workshop, GCE15, held in Boulder, CO September 30-October 1, 2015.The workshop was held in conjunction with the 3rd Workshop on Sustainable Software for Science: Practice and Experiences (WSSSPE3).GCE15 attracted 40 attendees, including international researchers from academia and industry, program officers, gateway developers, and students and faculty from underrepresented communities.Science gateways are web portals developed by and for communities of practice.They provide access to all types of resourcesremote instruments, curated data collections, supercomputers, and many others.They are used by scientists, engineers, researchers, and educators in many fields.The complex, digital, collaborative nature of research has resulted in accelerated growth of gateways.The purpose of science gateway workshops is to provide a forum to showcase science gateway projects and related technologies.The workshops feature keynote talks, contributed talks, and posters.This year attendees were able to set a portion of the agenda interactively through the use of Open Space Technology.The workshops also provide opportunities to publish, thereby furthering the exchange of knowledge in the gateway community.At the workshops, developers can learn from one another and learn about new technologies.Principal investigators can keep abreast of the state of the field.This special issue features contributions in the areas of technologies for building and operating gateways as well as experience papers describing fully functional gateways.

Science gateways are a solution for user communities to access applications and data via a graphical user interface. These graphical user interfaces hide the underlying infrastructure, as far as feasible and as far as desired by the users. In general, science gateways offer a single point of entry to create and/or analyze domain-specific data. Their core goal is to increase the usability and accessibility of computational tools and digitized data as well as to leverage reproducibility of scientific processes. While the user interfaces are especially tailored to the specific demands of a user community, the underlying infrastructures, for example, national or international distributed computing infrastructures (e.g., XSEDE), are mainly applicable for a wide range of use cases. Thus, science gateway frameworks and science gateway APIs, which offer building blocks for the management of jobs and data within such infrastructures, ease the implementation of science gateways for developers. The latter can focus on the domain-specific demands while reusing or extending available building blocks. The contributions to this special issue present the current state-of-the-art research and elucidate trends in the area of science gateways as well as demonstrate available solutions for the users. Submissions are grouped in five general areas: science gateway use and sustainability, generic development frameworks, novel workflow-oriented approaches, data management, and use cases from diverse domains. The statistics illuminate among other topics the increased usage of science gateways, which is also reflected in high number of submissions demonstrating specific use cases. Consequently, sustainability approaches have found their way into the special issue reflected not only in a submission about a model for sustainability but also in numerous submissions on developments and enhancements for generic building blocks of diverse existing mature science gateway frameworks and APIs. While novel approaches for workflow management and data management can be also considered under the enhancements for generic building blocks addressing new technologies such as mobile applications, they have already been core subjects for a couple of years and are presented in own sections emphasizing their importance for the science gateway community. The close collaboration between user communities and developers as well as providers is crucial for developing and offering effective science gateways widely used by science communities. Insights about the demands of user communities and about possibilities to support science gateway developers can immensely improve both the efficiency of creating science gateways and their long-term sustainability. Lawrence et al. 1 present results from a large-scale user survey of nearly 5000 researchers from diverse research domains and computer science departments involved in science gateway provisioning, who answered a questionnaire about demands on and existing courses for developing science gateways. Major topics include the support of user communities, aiding developers in choosing a suitable science gateway technology and involving specific expertise. The paper also notes that for the first time in the National Science Foundation (NSF's) supercomputing program, more users have accessed resources via gateways than by using the command line. The manuscript ‘Reflections on Science Gateways Sustainability Through the Business Model Canvas: Case Study of a Neuroscience Gateway’ 2 goes into detail on sustainability approaches for science gateways applying a methodology from lean business development, the Business Model Canvas. The authors adopted the model for the Amsterdam Medical Center Computational Neuroscience Gateway and suggest using the model as draft for science gateways in general for structuring various factors, which have to be considered not only by industry but also by providers of science gateways in academia. In the last 10 years, quite a few mature and reliable science gateway frameworks and APIs have evolved, which aid developers with building blocks for generic tasks such as authentication as well as job, data, and workflow management. Thus, these tasks can be efficiently implemented in diverse science gateways without the need to develop them for each science gateway from scratch. Marru et al. 3 present the science gateway API Apache Airavata and its roadmap. The open-source API offers rich features from connectors for multiple infrastructures (clusters, cloud, and grids) through workflow support, as well as data management capabilities to multi-language support. The use of Apache Airavata as middleware is described in ‘The GenApp Framework Integrated with Airavata for Managed Compute Resource Submissions’ 4. The GenApp Framework is designed for creating flexible user interfaces in general and for science gateways while considering aspects like re-submission. Thus, via the integration with Apache Airavata, the authors deliver a full science gateway framework for all layers of a science gateway—frontend, middleware, and connectors to diverse infrastructures. Cholia et al. 5 aspire to ease the development of science gateways by targeting the backend of science gateways. They demonstrate the Nice and Easy Web Toolkit (NEWT) platform, which consists of standards-based RESTful services for the application of HPC infrastructures. Once the services are integrated within High-Performance Computing (HPC) infrastructures, they allow for exploiting the resources via a common web API. NEWT has been applied at the National Energy Research Scientific Computing Center since 2010. A similar approach is followed by Caballer et al. 6. They have developed services for scientific virtual infrastructures on the cloud provisioned as Infrastructure-as-a-Service. The services allow for flexible allocation of resources with features for sharing them with other users, deploying and undeploying them and adding or removing resources dynamically. The manuscript goes into detail for three successful use cases. ‘Enabling Cloud Bursting for Life Sciences within Galaxy’ 7 targets also the provision of cloud services. The authors describe the ongoing efforts in creating a ubiquitous platform capable of simultaneously utilizing dedicated as well as on-demand cloud resources. While Galaxy is widely used especially by the life sciences community, the developed technologies are applicable for diverse research domains. The use of Galaxy as generic employable science gateway framework is also tackled in 8. The authors describe a domain-independent, cloud-based science gateway platform, the Globus Galaxies platform, which provides a set of hosted services that directly address the needs of science gateway developers and deliver a science gateway as service. Science gateways are often tailor made to provide a harness for and interface to advanced workflow tools. Two submissions presented novel developments integrated within workflow solutions. In ‘Mobile Application Development Exploiting Science Gateway Technologies’ 9, the authors present a mobile application connected to a workflow-enabled framework. Mobile devices are, of course, increasingly common and can be invaluable in some domains, for example, those requiring extensive fieldwork. This paper describes how the capabilities of mobile devices can be extended by using distributed computing infrastructures for visualization and analysis of large astrophysics datasets and also highlights areas where web-based gateways must be adapted to be mobile friendly. The interfaces will be further adapted as usage by astrophysicists increases. ‘WorkWays: Interacting with scientific workflows’ 10 also discusses how human endeavors can be assisted by workflows. In this example, human interactions with the workflow happen through a dynamic IO model where users can insert data into or export data out of a continuously running workflow dynamically. Previous Workways papers have demonstrated interactivity in the analysis of Magnetic Resonance Imaging (MRI) images and in aerospace design optimization 10. This submission includes the incorporation of Paraview Web for visualization, which is used in the analysis of the fluid flow through a ‘micromixer’. Here, the user can actually steer the computation by selecting a parameter space and having the optimization workflow focus on only the selected region. Data management is an increasingly time-consuming task for scientists and can be fraught with error. Gateways again can provide a natural interface to managing data effectively. Our first submission, ‘Remote Storage Management in Science Gateways via Data Bridging’ 11 actually connects challenges in data management with the challenges of workflows and distributed computing infrastructures described in the preceding section. A data bridging service called Data Avenue has been integrated into the WS-PGRADE/gUSE portal framework to provide a common interface to the myriad storage resources, thus streamlining the use of workflows that use many different underlying infrastructures. While not strictly a data management application, Araport 12 is an open-source, online community resource for discovery of both data and applications that support the study of the Arabidopsis thaliana genome through an app store-like approach. Users can both choose tools from Araport and contribute their own. User registrations have doubled because the launch of the Science Apps Workspace with over 30 registered app developers, so with all of this parallel effort there, will be tremendous leverage to the original investment. Five submissions addressed science gateway use cases. For the editors, the practical use of science gateways in a variety of fields is often the highlight of these workshops. ‘FACE-IT: A Science Gateway for Food Security Research’ 13 develops a framework for crop and climate impact assessments. Data are ingested from diverse geospatial archives and often require regridding and additional processing. Large-scale climate simulations, including agricultural models, are then conducted and comparisons made between regional and global models. Workflows are executed through the Globus Galaxies platform, and outputs are captured in well-defined, reusable and comparable formats. FACE-IT will be used to achieve the goals by the Agricultural Model Intercomparison and Improvement Project at the Center for Robust Decision-making on Climate and Energy Policy. Hu et al. also address agricultural issues in their submission, ‘CyberGIS-BioScope: A Cyberinfrastructure-based Spatial Decision-Making Environment for Biomass-to-Biofuel Supply Chain Optimization’ 14, although here, we are looking at agricultural production in support of biofuels. Here, although, the entire supply chain must be considered. This requires collaborative data integration, model specification, analysis, and coordinated implementation and management. As in the FACE-IT paper, preprocessing of the data is crucial for interoperability of data sources. Here, this is between bioenergy models and geographic information systems. Next, interactive scenarios are developed for evaluation and sharing, and as a final step, the optimization problem can be solved. CyberGIS-BioScope is the resulting product that accomplishes these tasks. The result is an interface that is tailored to both agricultural scientists and decision makers. In a completely different field, the IMP Science Gateway 15 is used to further virtual experimental labs and their use in multiscale courses in e-learning. IMP uses WS-PGRADE and gUSE technologies for molecular dynamics simulations of nanostructures. Workflow components are used as Lego-style construction units for learning modules of various duration and complexity. These learning modules can be used in a variety of settings—such as lifelong learning and vocational training. The final two use case submissions come from the medical field. ‘Building a Medical Research Cloud in the EASI-CLOUDS Project’ 16 describes a European research project that supports a group at Charite University Hospital with a high demand for computation to analyze MRI images. In order to meet the needs of this customer, the gateway had to integrate, monitor, and manage services all within a defined service level agreement (SLA). More on how this influenced design and their experiences meeting the SLAs. Science gateways are also used in the medical field in the area of computer-aided drug design in a process called virtual drug screening. Large amounts of often difficult to manage high-throughput computation are needed in this process. The Docking gateway 17 was developed to allow biochemists to easily conduct these screenings. In a nice development, the authors were able to reuse generic layers developed for a neuroimaging gateway. Data and computation management as well as operational support processes could all be reused. This really should become one of the hallmarks of science gateways. The submission highlights the user-centered design process, a contribution that should be of interest to many developers, and also includes a performance assessment of three different analysis approaches—a gLite grid, Hadoop (running on the Dutch Hadoop cluster), and a local cluster. The editors are once again pleased with the quality and variety of submissions to IWSG14 and GCE14 and the interest in and effort taken to submit extended papers for this special issue. We are grateful to both authors and reviewers for their invaluable help in making this possible.

This deposit includes (1) the invitation and reminder messages sent to the survey sample and (2) the survey questions, including instructions for branching.

This special issue represents an active collaboration between the organizers of two science gateway workshops.The International Workshop on Science Gateways 2013 has taken place in June 2013 in Zurich and the Science Gateway Institute Workshop 2013, held in conjunction with IEEE Cluster in September 2013 in Indianapolis.The workshops attracted together over 100 international researchers and have led to excellent presentations and publications on science gateway developments, workflow-centered enhancements, science gateway infrastructures, and developments in specific research domains such as the life sciences and health applications.Authors of accepted submissions to the workshops have been invited to submit extended versions for a special issue.This special issue consists of the accepted papers of a further peer review process.The increasing complexity of scientific study and the increasingly digital nature of data have resulted in a myriad of community-developed solutions.Advanced Web portals, also called science gateways, have emerged in many domains.They assemble the computational resources, data collections, visualization capabilities, collaboration tools, and even access to instruments that scientists need to conduct their research.Development of these gateways is also increasingly complex, and developers often find it quite valuable to learn from one another, even across domains.This special issue highlights accepted papers from two workshops.The Fifth annual International Workshop on Science Gateways, held June 2013 in Zurich and the Science Gateway Institute workshop, held in conjunction with IEEE Cluster held September 2013 in Indianapolis.Both workshops incorporated a peer review process.Authors of top papers from both events were invited to submit extended versions of their work for publication in this special issue.The purpose of these workshops is to provide a forum to showcase science gateway projects and related technologies.Developers can learn from one another and learn about new technologies, and principal investigators can keep abreast on the state of the field.This special issue features contributions in the areas of technologies for building gateways, workflows to enhance the capabilities of gateways, and infrastructures that support science gateways.Also featured are ready-to-use gateways in the life sciences and health applications fields.Providers of science gateway technologies aim at offering generic frameworks to ease the development of science gateways for a specific research domain while providers of distributed computing infrastructures work on supporting communities with computing and data resources.Such infrastructures require policies on usage and security, and the close collaboration with developers of domain-specific science gateways elucidates the demands in the specific research domain.Users of such a domain want to focus on their research questions and create and analyze data in an intuitive and efficient way-regardless of whether the underlying infrastructure provides resources in cloud, grid, or cluster infrastructures. TECHNOLOGIES FOR SCIENCE GATEWAY DEVELOPMENTThe development of science gateways can be distinguished in two main tasks.Firstly, the generic part, which is concerned with security features, accesses to underlying infrastructures and job, workflow, and data management.This part can be very similar for diverse science gateways.Frameworks or APIs support developers with building blocks so that there is not the need to develop such features

This special issue is based on presentations at the XSEDE13 conference held in San Diego, July 2013.The conference is an annual gathering of the extended community of those interested in advancing research cyberinfrastructure (CI) and digital resources.This includes researchers using XSEDE and like resources, XSEDE staff members, Campus Champions, and especially students.Seven hundred twenty people attended the conference, from 50 states, 1 territory, and 14 countries.As a summertime conference with terrific student programs from high school to post-graduate levels, we were fortunate to attract 200 students.From the Call for Participation, the purpose of the conference is to 'showcases the discoveries, innovations, challenges and achievements of those who utilize and support XSEDE resources and services, as well as other digital resources and services throughout the world'.The conference included tutorials, birds-of-a-feather sessions, a poster session, visualization showcase, and job fair.Each conference has a unique theme.In 2013, the focus was the impact of science gateways and the relevance of computation and high-end analysis in the biosciences.The core technical program consisted of four tracks-science and engineering; technology; software and software environments; and training, education, and outreach.Selected papers from the core technical program were invited to expand content and submit to this special issue. SCIENCE AND ENGINEERING TRACKXSEDE13's science track received 47 submissions, 27 of which were accepted for the conference.Eight of the best were asked to develop extended papers for inclusion in this special journal issue.Papers in the science track covered various research topics and all of them involve utilizing XSEDE resources in innovative ways.Research topics span wide areas such as biological sequence analysis, modeling of energy usage in buildings, analysis of error correcting codes (ECC) for simulations on GPUs, the impact of Campus Bridging for researchers transitioning to XSEDE resources, algorithms for computational finance analyses, methods enabling improved search capabilities over large digitized document archives, and the implementation of algorithms on Intel Xeon Phi coprocessors.The paper on functional annotation of newly sequenced genomes [1] describes an optimized workflow to enable large-scale protein annotation.It utilizes a special classification algorithm and high performance computing (HPC), and the demonstrated results show capabilities which scientists will be able to utilize to annotate big genome data.The Building Energy Modeling (BEM) approach is combined with machine learning methods in another paper [2] to enable efficient modeling of US buildings.The parametric space makes the use of supercomputers a necessity, and the results are utilized to train machine learning algorithms.Another paper [3] looks at ECC available on many of the modern graphics processing units (GPUs) used in HPC machines.It looks at the penalty involved in utilizing ECC and compares molecular dynamics simulation results regarding ECC events triggered during such simulations.It discusses if error checking is necessary for such simulations given the penalty associated with it.Transitioning from campus resources to XSEDE resources is not an easy task for researchers.Making Campus Bridging Work for Researchers [4] proposes utilization of Campus Bridging experts to make this transition easier while requiring minimal investment from the organizing body.

Over the last fifteen years, science gateways have proven to be fertile ground for cyberinfrastructure research, while at the same time dramatically increasing the usage and accessibility of cyberinfrastructure to scientists and educators. Gateway developers, however, still face many challenges in building and operating these complex infrastructures that address the dynamic and emerging challenges of computational infrastructure. Through the XSEDE Science Gateway Program, we propose to solicit information on the knowledge, experience, and software from widely used science gateways. We will compile the information into a “Science Gateway Cookbook” which will democratize the experiences in developing, operating, and sustaining science gateways. We hope this will be a good literature reference and also avoid some repetition in the development process.

Problem solving environments (PSEs) are increasingly important for scientific discovery. Today's most challenging problems often require multi-disciplinary teams, the ability to analyze very large amounts of data, and the need to rely on infrastructure built by others rather than reinventing solutions for each science team. The TeraGrid Science Gateways program recognizes these challenges and works with science teams to harness high-end resources that significantly extend a PSE's functionality.

Abstract Science gateways have emerged as a concept for allowing large numbers of users in communities to easily access high‐performance computing resources which previously required a steep learning curve to utilize. In order to reduce the complexity of managing access for these communities, which can often be large and dynamic, the concept of community accounts is being considered. This paper proposes a security model for community accounts, organized by the four As of security: Authentication, Authorization, Auditing and Accounting. Copyright © 2006 John Wiley & Sons, Ltd.

Increasingly, scientists are using portals and desktop applications as to access computational capabilities, information services, data collections, instruments and other resources. Developers are building community-specific tools and applications that are integrated via a portal or a suite of applications, providing access to high end resources. These gateways often support orchestrated workflow, resource directories (databases, compute resources, etc.), and execution services.The purpose of the BOF is to bring together developers, researchers or resource providers who are developing, deploying or using these types of capabilities to discuss common issues including usage models, authentication and authorization, access mechanisms and what to consider when accessing shared resources.

Abstract One benefit of a computational Grid is the ability to run high‐performance applications over distributed resources simply and securely. We demonstrated this benefit with an experiment in which we studied the protein‐folding process with the CHARMM molecular simulation package over a Grid managed by Legion, a Grid operating system. High‐performance applications can take advantage of Grid resources if the Grid operating system provides both low‐level functionality as well as high‐level services. We describe the nature of services provided by Legion for high‐performance applications. Our experiences indicate that human factors continue to play a crucial role in the configuration of Grid resources, underlying resources can be problematic, Grid services must tolerate underlying problems or inform the user, and high‐level services must continue to evolve to meet user requirements. Our experiment not only helped a scientist perform an important study, but also showed the viability of an integrated approach such as Legion's for managing a Grid. Copyright © 2004 John Wiley & Sons, Ltd.

One benefit of a computational grid is the ability to run high-performance applications over distributed resources simply and securely. We demonstrate this benefit with an experiment in which we studied the protein folding process with the CHARMM molecular simulation package over a grid managed by Legion, a grid operating system. High-performance applications can take advantage of grid resources if the grid operating system provides both low level functionality as well as high-level services. We describe the nature of services provided by Legion for high-performance applications. Our experiences indicate that human factors continue to play a crucial role in the configuration of grid resources, underlying resources can be problematic, grid services must tolerate underlying problems or inform the user, and high-level services must continue to evolve to meet user requirements. Our experiment not only helped a scientist perform an important study, but also showed the viability of an integrated approach such as Legion's for managing a grid.