From the website....
For over a decade, Paradox Interactive has been a leading global publisher of PC-based strategy games with a particularly strong presence in the United Stated and Europe. Its steadily-growing portfolio includes firmly established PC franchises such as the critically acclaimed Europa Universalis and Crusader Kings series of games, created by Paradox Development Studio, as well as the award-winning Magicka and Mount & Blade titles.
2013-2014 will play host to Paradox Interactive’s most ambitious lineup of titles to date with such anticipated releases as Magicka: Wizard Wars, Europa Universalis IV and War of the Vikings. It is also expanding its presence onto tablets and cross-platform gaming.
We work with renowned distributors worldwide and are present on all major digital download portals. We share a passion for gaming and gamers, and our goal is to provide deep and challenging games with many hours of gameplay to our growing 650,000 + member community."
So yeah, in their own words, they are a publisher.
"I like dogs playing poker... because dogs would never bet on things; so it's incongruous. I like incongruity." - Christian Wolff