As the name suggests, Open 3D Model Viewer is a dedicated free and open-source 3D file viewer for Windows 11/10. In it, you can visualize 3D models of formats including 3DS, OBJ, PLY, DAE, STL, etc.

BitRecover EML File Viewer is a free EML file viewer for Windows 11/10. Using it, you can view small as well as large EML files with their attachments and more.