Open source digital marketing tools provide small businesses with cost-effective and customizable options for improving their online presence. These tools include WordPress for content management, GIMP for graphic design, Mailchimp or OpenEMM for email marketing, Hootsuite or Mastodon for social media management, and Google Analytics or Matomo for analytics. Open source tools offer a range of benefits, including the ability to add features and functionality, greater control over data and workflow, and more privacy.