lessmsi is described as 'This is a utility with a graphical user interface and a command line interface that can be used to view and extract the contents of an MSI file' and is an app. There are five alternatives to lessmsi for a variety of platforms, including Windows, Linux, Android, Android Tablet and BSD. The best alternative is Universal Extractor 2, which is both free and Open Source. Other great apps like lessmsi are InnoExtractor, innoextract, Innounp and Inno Setup Extractor.
Universal Extractor 2 is an unofficial updated and extended version of the original UniExtract by Jared Breland. It brings several hundred changes including community-wanted ones such as a batch mode, auto-updater and scan-only-functionality.