As nouns the difference between koss and foss
is that koss is alternative form of lang=en while foss is an alternative spelling of lang=en.
As an acronym FOSS is
free and Open Source Software.
As a proper noun Foss is
{{surname|lang=en}.
koss
English
Noun
(koss)
----
foss
English
Acronym
(Acronym)
(head)
Free]] and [[open source, Open Source Software
Derived terms
* FOSSer