Virtualization technologies have evolved along with the development of computational environments since virtualization offered needed features at that time such as isolation, accountability...

Singularity containers introduce a compelling means for unlocking the implied dependency between application toolchains and operating system. By encapsulating everything but the kernel in a single file, Singularity containers decouple the runtime and allow it to be highly portable in a trusted way..

The general availability of Red Hat Enterprise Linux 8 was announced this week at the Red Hat Summit in Boston. In this special guest feature, Ian Lumb writes that the company's Singularity containers can ease the transition to RHEL 8. "RHEL 8 is a transition over time, not a discrete event in time. Singularity containers preserve your heavily vested legacy deployments, while enabling you to make the transition on your terms."

Over at Argonne, Nils Heinonen writes that Researchers are using the open source Singularity framework as a kind of Rosetta Stone for running supercomputing code almost anywhere. "Once a containerized workflow is defined, its image can be snapshotted, archived, and preserved for future use. The snapshot itself represents a boon for scientific provenance by detailing the exact conditions under which given data were generated: in theory, by providing the machine, the software stack, and the parameters, one’s work can be completely reproduced."

Here we present Singularity, software developed to bring containers and reproducibility to scientific computing. Using Singularity containers, developers can work in reproducible environments of their choosing and design, and these complete environments can easily be copied and executed on other platforms. Singularity is an open source initiative that harnesses the expertise of system and software engineers and researchers alike, and integrates seamlessly into common workflows for both of these groups. As its primary use case, Singularity brings mobility of computing to both users and HPC centers, providing a secure means to capture and distribute software and compute environments. This ability to create and deploy reproducible environments across these centers, a previously unmet need, makes Singularity a game changing development for computational science.

Diversity and complexity are all good requirement refinement enablers, mainly in what concerns software stack.