You can open the currently edited file in any other application from within Kate. Choose File -gt; Open With for the list of programs configured for the document type. There is also an option Other... to choose any application on your system.
Jo kinne fanút Kate de no bewurke triem iepenje yn allyk hokker oare applikaasje. Kies Triem - gt; Iepenje mei foar de list mei programma' s konfigurearre foar it dokumint type. Der is ek in opsje Oar... om in oar, op jo systeem steande applikaasje te kiezen.