Omnisphere, Keyscape, Stylus RMX, and Trilian all have their own standalone application. This can be useful for live performances, or other situations where you don't need your DAW or Host to record your music.
Your standalone applications can be found in this location:
Macintosh HD/ Applications
C: ProgramData Spectrasonics
Note: To turn on Hidden Files and Folders in Windows 7 and later, go to Control Panel/ Appearance and Personalization/ Folder Options/ View Tab and select Show Hidden Files and Folders. Hit Apply.
If you do not see your Spectrasonics app icon in the locations above, make sure you have performed a complete install and are up to date.
If you want to know where your other software files are, please refer to this knowledge base article here.