Translation:The use of Pasporta Servo is an adventure.
I think some people have a different reading of the sentence. To use celo/purpose is an entirely different meaning, implying that the purpose of that Organization, Pasporto Servo, is to foster or create adventure. Uzo/use implies that using that service is a way of finding adventure.
Well, to be fair, though, 'Microsoft' is recognized as a trade name, but the name itself is not terribly descriptive as far as its components go, whereas the two words that comprise the name of our 'Pasporta Servo' are recognizable as simple, standalone elements which are totally descriptive of the service itself, yet in a rather non-proprietary way...
There is some sort of a precedent, at least, for 'la pasporta servo;' the exact phrase returning "proksimume 5,720 rezultoj."
Though it's not set in stone due to linguistic baggage the Esperanto speakers have, in general Esperanto tends to not use "la" for organizations and such, unlike a fair number of European languages. E.g. the World Esperanto Association is usually just "Universala Esperanto-Asocio" or "UEA", and not "la Universala Esperanto-Asocio" or "la UEA".
The same is true for the United Nations ("Unuiĝintaj Nacioj" and "UN" instead of "la Unuiĝintaj Nacioj" and "la UN"), and the European Union ("Eŭropa Unio" and "EU" instead of "la Eŭropa Unio" and "la EU"), and similar organizations.
That's just what RaizinM was talking about: in English "the" is needed, that's Esperanto that does not demand "la" in similar cases. (Not very handy when neigher English nor Esperanto is one's native language, so both sets of nuances have to be learned during one Duolingo course xD)