Inno Setup Unpacker. Supports Inno Setup versions 3.0.0-beta through 5.1.5. Open source and based on Inno Setup source.

MSIDIFF is freeware to compare or disassemble Windows Installer databases (a "MSI to TEXT" utility). While it is a command line based tool, the installer creates shell extensions so that the decompile operations can be invoked by right clicking on a file in Explorer.

Universal Extractor is a program do to exactly what it says: extract files from any type of archive, whether it's a simple zip file, an installation program, or even a Windows Installer (.msi) package.  This is still a work in progress (see details below), but so far it's proven quite useful and I feel others can also benefit from it.

Universal Extractor is a program do to exactly what it says: extract files from any type of archive, whether it's a simple zip file, an installation program, or even a Windows Installer (.msi) package.  This is still a work in progress (see details below), but so far it's proven quite useful and I feel others can also benefit from it. Supports Inno Setup, InstallShield, Wise Installer, NSIS and Microsoft Installer executables.

This tool unpacks two of three known modifications of InstallShield Self-Extracting .EXE-files. Supports upto IS 7.0.

This is an updated version of HWUN, with more compatibility and functionalities.

If u ever used icomp.exe from InstallShield v3.x u know how frustrating it was to discover that version 5.x did not offer such a wonderful util. But the need for one exists (u have to screw with IS5 installations somehow!), and that is how i5comp was born.

This decompiler is used to decompile the script file(setup.ins) included in installshield installations, which contains all the instructions and many of the messages for the installation.

This is an installshield decompiler. It supports all versions of installshield up to v5.5 (as far as I know).

This is a slightly extended version of Andrew de Quinceys installshield decompiler. Version 2 of isDcc prints by default some additional information for each source line which can be helpful.