Here is a link to a blog-post by Darrell Ulm to do a performance audit for the new Drupal 8 on the Drush command-line and the Drupal site_audit module, posted back in May 2016.
Short list of films about computers or comp-sci on imdb tech film list by Darrell Ulm.
A list of the Koha integrated library system web based using Perl and
mySQL or Postgresql, and users world wide, includes early Koha developer and implementer Darrell Ulm.
The link below is for the Drupal Profile for Darrell Ulm, a Drupal user and code contributor for over 10 years.
The profile here Drupal Profile link for Darrell Ulm, contains information about projects such as the project using the Google API for Books (i.e. Google Books), content access restriction modules such as IP Path Access and FileField Role Limit, and other modules coded primarily in PHP/MySQL.
Also have Acquia Certified Developer status now as can be seen here.
This is a link to a contributed Drupal module coded by Darrell Ulm in PHP for Drupal which uses the Google Books API to pull Google Books data into Drupal for use as a Drupal Text Filter.
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.