I've received a number of reports that download links are not working on the ODK website.
I can confirm that https://opendatakit.org/downloads/download-category/aggregate works, but clicking on any the specific links on that page leads to a blank page.
I've tried other tools pages (e.g., Collect, Build) and they fail. I've tried Chrome, Firefox, and Safari and they both fail.
From my quick research, it looks like the Download plugin on the Wordpress site was updated (perhaps automatically) yesterday and that seems to have broken the site.
I've alerted the folks in charge of the site and update this topic as I learn more.