In my native language, smartphone is a loanword. In Esperanto, I'd expect a kunmetaĵo. So far, I haven't seen any standard, and this surprises me. I've considered saĝtelefono, ruztelefono and inteligenta telefono. Are any of them right? How should I say smartphone?
Komputiltelefono is a kunmetaĵo built according to normal Esperanto rules and doesn't calque the very specific uses of the English words "smart" and "intelligent". It's easy to understand and some people already use it; Google gives a few hits.
The word is quite long, but keep in mind that in most contexts you can just say telefono. The use of komputiltelefono can be restricted to cases where you need to stress that you are talking only about smartphones and excluding all other phones.
ReVo proposes kompufono, among others. It is not really a kunmetaĵo, rather a merge between komputilo and telefono (a new root, in fact). But it conveys well the idea of a phone integrating the capacities of a computer. Saĝtelefono and inteligenta telefono are a bit inappropriate, since the device itself can not be said saĝa / inteligenta, only the people who designed it could be.
Poŝtelefono. I agree with Vanege - no need to literally translate all marketing terms from any language (unless internationalised already). Computer means any age computing device from main to personal, old/smart...
My 1st 'smart'phone was Siemens from 2001 Java/SD card/PC connectable mobile telephone, which is now dumb compared to recent ones. If we can call mobile telephone a device that does much more than transferring voice, why call smartphone something that in few years becomes dumb for the new generation. To specify non 'smart'phone I would say old mobile = Malnova Poŝtelefono. Same telephones with different version OS cannot run the same programs. Let Esperanto simplify the messy synonyms that English introduces.
Aptelefono. The main difference between these phones and previous types of mobile phones is that it is possible to install apps on the. By now, the neologism apo for "app" is well-established (certainly the language app Amikumu created by Esperantists has contributed to this, as it was advertised as an apo in Esperanto publications). Given that this allows to express the idea of a smartphone very concisely and clearly, I think it is to be preferred over other possible choices.
Of course, in most contexts it is enough to say telefono or, if necessary, poŝtelefono. The more precise term aptelefono should be reserved to context in which this level of precision is really required.
En Monato aperas ankaŭ la termino lerta telefono, kiu laŭ mi pli taŭgas ol saĝa telefono. Saĝa signifas „Posedanta ĝustan juĝkapablon” kaj telefonoj ne tre kapablas juĝi.
Ĝenerale tamen poŝtelefono sufiĉas. Apenaŭ plu ekzistas poŝtelefonoj, kiuj ne estas lertaj.
Aliaj sinonimoj: aptelefono (telefono, kiu uzas apojn, tio estas malgrandaj aplikaĵoj), karestelefono (ĉar la ekranon oni ofte kvazaŭ karesas por iri al alia parto de la menuo).
As there is some disagreement, why not a neologism smartfono? It is quite understandable internationally - and neologisms are an acceptable way to extend Esperanto.
- Easy on novices to Esperanto.
- Evades some discussions on correctness of terms, abbreviations, new roots.
- Is a more safe solution than betting that one term wins general acceptance - here. On the other hand picking one choice is like voting for it.
- The term poŝtelefono / telefoneto is more general - so does not fit.
The discussion shows a wish for language purity and in case of kompufono maybe a evasion of an English loanword. However it should not enforce learning more without an aha effect as with for instance the not mentioned komputofono. Having some wrong terms out there, simply falling back to a neologism is worth the effort. It has not done any damage to have both hospitalo and malsanulejo.