Design Web Format (DWF) represents 2D/3D drawing in compressed format for viewing, reviewing, or printing design files. It contains graphics and text as part of design data and reduces the size of the file due to its compressed format. The reduced file size makes the distribution and communication of rich design data efficient. DWF doesn't require the recipient to know about the usage of CAD software that created the original drawing.
Files with .OTP extension represent presentation template files created by applications in OASIS OpenDocument standard format. The contents of such a file include presentation information in the form of slides with text, images, shapes, multimedia content, transition effects and other slide elements. These template files are used for creating new presentations quickly based on the styling information stored in the template itself. OTP files can be created and saved with several different applications such as Impress that comes with OpenOffice suite and Microsoft PowerPoint. The OTP file format is similar to Microsoft PowerPoint template files .POT and .POTX.
You can also convert DWF into many other file formats. Please see the complete list below.