1. The 500 builds of 300 applications in the HeLmod repository will at least get you started on a full suite of scientific applications
Aaron Kitzmiller, John Brunelle, Michele Clamp, James Cuff
Informatics and Scientific Applications, Research Computing
Faculty of Arts and Sciences
Harvard University
18 May 2018
FAS | Research | Computing

2. Scientific software publication is easier than ever…
Distribution via PyPi, CPAN, github, DataVerse, Figshare.
Journals will publish scientific software (
Articles like this (“Publish your computer code: it is good enough”) encourage software publication
No generally agreed up standards
18 May 2018
FAS | Research | Computing

3. …resulting in a dizzying array of delivery mechanisms
Linux distro package managers (yum, apt-get)
Autotools, Cmake
Hand-edited Makefiles
Things that look like autoconf, but aren’t
Poorly constructed binaries
Language interpreter-specific tools (Python/pip, R/install.packages, Perl cpan) that work pretty well except when they don’t
Completely custom scripts that prompt for information
Homebrew, Linuxbrew
Custom dependency managers
Whatever boost uses
18 May 2018
FAS | Research | Computing

4. FAS | Research | Computing
… and a huge software maintenance burden that a standard module-based system cannot effectively address
18 May 2018
FAS | Research | Computing

5. FAS | Research | Computing
Harvard Extensions for Lmod
HeLmod uses rpmbuild, spec files and scripts to construct reproducible, shareable Lmod deployments
Lmod ( forces you to choose a compiler (and MPI) version before loading modules
Different versions of the same module cannot be loaded together
Bash scripts and RPM macros support build iterations over multiple compiler (and MPI) combinations
RPM Spec files explicitly detail the successful build procedure.
18 May 2018
FAS | Research | Computing

6. FAS | Research | Computing
18 May 2018
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7. FAS | Research | Computing
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18 May 2018
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9. We went through the pain so you don’t have to
18 May 2018
FAS | Research | Computing