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.PPSM File Extension

File Type	PowerPoint 2007 Macro-Enabled Slide Show
File Format	File
Common?	No
File Description	Non-editable PowerPoint slide show format that contains embedded macros; used for playing back slide shows created in PowerPoint 2007; based on the Open XML format introduced in Office 2007
Program(s) that open ppsm files	Mac / Windows: Microsoft PowerPoint 2007, PowerPoint Viewer, or previous versions of PowerPoint with Open XML document support

Information from FileInfo.com - The File Extensions Resource.
http://www.fileinfo.com/extension/ppsm