Aug 24, 2017 drulm pushed to 8.x-1.x at drulm/google_books_drupal_8 1b43688 Fix image display option, clean up code
Github is taking over the online software development repository sphere, and certainly have a huge market share of all online managed software projects, Open Source and proprietary.
Here is the Github account profile page with source code in C#, C/C++, PHP, ASM and others for Darrell Ulm and other links to this information can be found at the following: Profile, Tumblr and Blogger.
GitHub is a great tool for software development making most tasks more streamlined and helping multi-developer projects come together more cleanly with a smooth workflow.
From the Library Technology Guides, October 22, 2010 reference, and includes other contributors and notes about the Koha Integrated Library Software Open Source code release.
Here is the link for the Koha 3.2.0 announcement, reference to Darrell Ulm as code contributor.
Link shows past work, much has moved to GitHub for Darrell Ulm.
For work that was done further back before GitHub, some information is at: Darrell Ulm, Open Source Software profile at OpenHub, which is an interesting site to show open source contributions.
The link shown on this page includes reference to Darrell Ulm, on 4/2/2008, becomes the 57th code committer to Koha. And here is the History of Koha, and Open Source Integrated Library System.