olemus
rakendusprogramm, mis ühildub teise süsteemi
riistvaraga ja operatsioonisüsteemiga,
on installitav muutmata süsteemi konfiguratsiooniteavet,
on käitatav ka ird-andmekandjatelt (mälupulk, DVD)

Computerlanguage.com:
(1) an application that can be converted from one computer environment to another
(2) an application that can be easily moved from one computer to another
(3) an application stored on a USB flash drive that can run on a computer without leaving any trace of itself when the application is finished

ülevaateid
https://en.wikipedia.org/wiki/Portable_application

https://en.wikipedia.org/wiki/List_of_portable_software