Open IPO File
The IPO file extension takes as its format a direct association with the InstallShield utility in its Professional Edition.
More about InstallShield
InstallShield is used for the creation of installation programs or software packages designed primarily for the Windows operating system.
InstallShield is used to install software for Microsoft Windows desktop and server platforms, though it can also be used to manage applications and software packages on a variety of handheld and mobile devices, including Linux.
The utility is currently developed and maintained by Revenera Software.
In this case, the IPO file extension is attributed to the InstallShield Object Project files, hence the acronym IPO, which serve as the basis for InstallShield installation packages.
IPO files store scripts, or directory structures, settings for an installation dialog, etc.
An IPO file can be used in your own setup project or shared with other software developers.