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European Environment for Scientific Software Installations

The European Environment for Scientific Software Installations (EESSI, pronounced "easy") is a collaboration between a number of academic and industrial partners in the HPC community. Through the EESSI project, they want to set up a shared stack of scientific software installations to avoid not only duplicate work across HPC sites but also the execution of sub-optimal applications on HPC resources.

They want to focus not only on the performance of the software, but also on automating the workflow for maintaining the software stack, thoroughly testing the installations, and collaborating efficiently.

For end users, they want to provide a uniform user experience with respect to available scientific software, regardless of which system they use. The software stack is intended to work on laptops, personal workstations, HPC clusters and in the cloud, which means we will need to support different CPUs, networks, GPUs, and so on. We intend to make this work for any Linux distribution, and a wide variety of CPU architectures (Intel, AMD, ARM, POWER, RISC-V).

Installing your own software

As the EESSI platform develops, we will expand the documentation to include the case where you would like to install your software building upon the EESSI stack. Of course you are always free to install your software however you see fit, but you should be aware that (at least) two powerful tools exist to facilitate this, EasyBuild and Spack.


EasyBuild is a software build and installation framework that allows you to manage (scientific) software on High Performance Computing (HPC) systems in an efficient way. It is motivated by the need for a tool that combines the following features:

  • a flexible framework for building/installing (scientific) software
  • fully automates software builds
  • divert from the standard configure / make / make install with custom procedures
  • allows for easily reproducing previous builds
  • keep the software build recipes/specifications simple and human-readable
  • supports co-existence of versions/builds via dedicated installation prefix and module files
  • enables sharing with the HPC community (win-win situation)
  • automagic dependency resolution
  • retain logs for traceability of the build processes

Since EasyBuild is what underpins the software applications of EESSI, you are likely to find the integration with the EESSI to be extensive.

There is a one day introduction to EasyBuild at


Spack is a package management tool designed to support multiple versions and configurations of software on a wide variety of platforms and environments. It was designed for large supercomputing centers, where many users and application teams share common installations of software on clusters with exotic architectures, using libraries that do not have a standard ABI. Spack is non-destructive: installing a new version does not break existing installations, so many configurations can coexist on the same system.

You can find a one-day introduction to Spack tutorial at

Last update: March 11, 2021