Target Environment
The Target Environment tab defines the operating system, windowing system, architecture and locale for which you are developing your plug-ins.
Typically, a plug-in is agnostic to its environment and should run in all environments. However, if you have platform-specific resources or code, it is recommended to package them in a plug-in fragment that declares the platform with which it is compatible.
For example, the org.eclipse.ui.win32 fragment has the following filter in its MANIFEST.MF:
Eclipse-PlatformFilter: (ws=win32)
This filter indicates that the org.eclipse.ui.win32 fragment is designed to run only on platforms with a win32 windowing system. If a user attempts to run Eclipse on a platform that does not meet this requirement, the fragment will be silently ignored by the runtime.