A file with .igs (Initial Graphics Exchange) extension is a 2D-3D design exchange file format that is independent of source or destination file format specifications used by CAD applications. It is used to exchange design information about circuit diagrams, wireframes, the freeform surfaces between two independent systems. IGS files can be opened by applications such as Autodesk, FreeCAD, CADEX CAD Exchanger, and other similar applications.
PPSX, Power Point Slide Show, file are created using Microsoft PowerPoint 2007 and above for Slide Show purpose. It is an update to the PPS file format that was supported by Microsoft PowerPoint 97-2003 versions. When a PPSX file is shared with another user and opened, it starts as PowerPoint show unlike PPTX file that opens in editable mode. The sequence of slide show is the same as in the original presentation. All the slides accompany the images, sounds and other embedded media accompany the presentation slides to the PPSX during the slideshow.
You can also convert IGS into many other file formats. Please see the complete list below.