Can I download MPLAB IPE as a standalone app?
Someone asked this recently on one of the Microchip forums, and submitted a ticket.  The response from Microchip was:

It is not possible to install IPE as a stand alone application.

The IPE uses the MPLAB X IDE frame work, MDB database and hardware tool interfaces
and respective drivers to provide programming capabilities to the end user.
The following software must be installed on your PC to use the IPE application:
    •    MPLAB X IDE v1.20 or greater.
    •    The MPLAB IPE application (installed automatically with MPLAB X IDE).


However this is contradicted to some degree by this page, which says:

The (MPLAB X) installer can install both MPLAB X IDE and MPLAB IPE, or you can
choose to install just one of the programs during the installation process.


So it sounds like you cannot download just the IPE and install it, but you can download the entire package (IDE+IPE), around 350 MB and just install the IPE (which presumably also installs the extra pieces of the package like the database etc. needed by the IPE). However this would allow the person to install the IDE, so it doesn't look like you can prevent that.