Installer merge module created with Wise Package Studio, an installer creation utility; stores files and installation settings in a single package, which can be installed on Windows systems. Files can be added or removed from WSM packages using Wise Package Studio. Once a package has been modified, it must be recompiled into a merge module by Wise Package Studio in order to function correctly. WSM files are similar to .MSM files, but are used specifically by Wise Package Studio. NOTE: Symantec discontinued Wise Installation Studio and Wise Installation Express on April 19, 2010.