Excellent Writing on Digital Library Software Sustainability

The Library of Congress blog The Signal: Digital Preservation has an excellent guest post, “Why Can’t You Just Build it and Leave it Alone?” by Marie Gallagher (computer scientist in the Lister Hill National Center for Biomedical Communications at the U.S. National Library of Medicine/NLM) with the post is based on “Improving Software Sustainability: Lessons Learned from Profiles in Science“, an interactivepaper (pdf) at the Society for Imaging Science and Technology’s Archiving 2013 conference, April 2-5, 2013.
The post is excellent because it concisely explains the ongoing work required for digital library functionality as part of the overall work for sustainability, providing excellent images showing the changes in software and components over time with those changes necessary to support core and new core functionality. As anyone who’s been asked on software “Why can’t you build it and leave it alone” or “why does something need ongoing development for anything other than new features”, the post offers an excellent and clear example and explanation of the need. The post is worth reading in full (and likely quoting and referencing frequently) as shown even in this brief excerpt:

The effort needed for ongoing software upgrades and replacements will come as no surprise to software architects, developers, programmers, security experts and others who use or develop software.  But the need may be less obvious to anyone more removed from these activities.  The ongoing need for upgrades and replacements has sometimes prompted the question, “Why can’t you just build it and leave it alone?”
[…] Clearly some changes were necessary in order to add new features.  But avoiding adding new features still would not have eliminated the need to make replacements and upgrades.  Some software replacements and upgrades were necessary because of external threats to the stability of our software.  Some of these threats included hardware or operating system incompatibilities, loss of backward compatibility, loss of needed functions, new policy requirements, product abandonment, product support/licensing costs, security flaws and software bugs.  Not responding to these threats could have eventually resulted in inability to create or edit metadata and digital items as well as lack of access to our digital items and metadata–not to mention exploitation of security flaws to do harm to our systems or others.

This is a great post and well worth reading. It’s also well worth quoting, referencing, and citing to help improve awareness of what sustainability means and what resources are required for digital libraries.