The Platform Assistant server (named paserver) is a command-line application that can be installed on Windows and Mac OS X. You install the Platform Assistant on a remote system, in the same network as your development system, to let RAD Studio interact with that remote system, so that you can develop cross-platform (multi-device) applications for Mac OS X, iOS, or Win64 (this last from a Win32 development system).
The Platform Assistant allows you to develop multi-device applications and to debug applications remotely.
The Platform Assistant needs to be running and connected to the IDE in order for you to do the following:
Run and debug multi-device applications remotely (Win64, Mac OS X, iOS).
Deploy multi-device applications (Win64, Mac OS X, iOS).
Add to RAD Studio a local copy of a Mac OS X or iOS SDK, which is a prerequisite for developing either of the following:
Delphi or C++ iOS apps
C++ desktop applications for Mac OS X