A company producing products compatible with Ars Magica.
From TPK Productions website:
TPK Productions is a company dedicated to drilling holes through the hard part of the wood. We publish roleplaying game material using the Open Gaming and M&M Superlink licenses, usually in .pdf format through companies like RPGNow, e23, and Paizo.
We believe roleplaying should be fun, that it should make you think, and that a quality RPG can be good for you. We believe clip art is Fine, but full color character art is Near Mint. We believe research is never wasted. We believe every product we put out should make you, the reader, sit up in your chair and say, "Holy $#!% that's good!" Do we succeed?
That is what you must tell us.