Procore - Procore is the world's most widely used construction project management software. Easy to use, mobile platform with unlimited user licenses.
Grav - The modern open source flat-file CMS
Autodesk BIM 360 - Autodesk BIM 360 is a construction project management software.
WonderCMS - WonderCMS is the smallest flat file CMS. Completely free, open source, privacy oriented for over 12 years.
Bluebeam Revu - The end-to-end digital workflow and collaboration solution trusted by over 1 million AEC professionals worldwide. Revu delivers award-winning PDF creation, editing, markup and collaboration technology designed for AEC workflows.
HTMLy - HTMLy is an open source databaseless blogging platform. A Flat-File Blog and Flat-File CMS written in PHP prioritizes simplicity and speed.