Virtual Laboratories are, in a broad sense, environments for distance collaboration and experimentation using distributed information and communication technologies. Virtual laboratories are enablers of e-Science applications: they can be designed for data collection, processing and dissemination, for long-term storage of data, documents and workflows associated with e-Science applications as well as to provide access to otherwise inaccessible data and/or expensive real instruments. Virtual laboratories, in particular the ones associated with data-intensive science, became a reality due to the availability and ubiquitousness of modern IT technologies and infrastructure (web and multimedia applications, cluster and cloud computing, collaboration software, social networks, etc.) and to the demands that data-intensive science imposes (data availability, experiments reproducibility, data provenance, etc.). Virtual laboratories solutions are usually implemented in an ad-hoc fashion: scientists and developers select technologies that are adequate to solve each of their specific problems and develop or integrate tools that compose such a lab. Since the solution is ad-hoc, it may not be packaged as a new software component that can be used as-is for other types of virtual laboratories, but the decision on particular technologies and the tools devised with these technologies may yield interesting and valuable lessons that can be applied in other applications. The focus of the workshop will be on why scientists chose particular tools and how the virtual laboratories were developed. Of particular interest are case studies with lessons learned; ideas that could lead to the informed selection of tools and technologies and new software approaches to the management of virtual laboratories. The goals of the workshop are the presentation of the computational aspects of the virtual laboratories and exchange of ideas on how to devise better solutions for these applications. Attendees will gain valuable information from other experiences and create new contacts for further development of their own virtual laboratories.