From the About us page:
Moment (MMT) provides free CC0 photography for personal and commercial use on websites, projects, themes, apps, and more. I launched MMT in 2014 to share my love of photography with the world. Over the years I’ve taken countless photos and wanted to post some of those photos to use for free and give back to the online community. The content spans many categories, including nature, city scenes, workspaces, and macro photography. These photos can be freely downloaded, used, and redistributed for both personal and commercial purposes.