Risto Kupsala (born 1979) is a Finnish auxiliary language activist, who advocates auxiliary languages with cross-cultural ideology especially in lexicon. He is the creator of Pandunia, a minimalistic worldlang. He initiated a multilingual dictionary project called Mulivo in 2005.
In 2002 Kupsala published an IAL sketch under the name Lone. The language showcased isolating grammar and pan-european vocabulary. Kupsala participated briefly Gaja and Demos projects, which were/are group efforts for creating new auxiliary languages. He also helped in early phases of the development of Neo Patwa.
In Demos Kupsala came up with the idea of phonological pivot system, which is a way to solve the problem of putting together languages with incompatible stop series. The problem comes about, for example, when some source languages or prospective speakers distinguish voiced and unvoiced stops and some others aspirated and unaspirated stops. The proposal was countered with the phonological shift system.