Semi spell casters are those professions who combine the use of arms with a limited access to a realm of magic, typically to enhance their use of arms or skills.  These professions have also been divided into the three realms for ease of reference.

Essence:
Dabbler: Uses magic to enhance his subterfuge and mechanical endeavors (FRP page 99)
Monk: Uses magic to enhance his movement and body control (CL page 26)

Channeling:
Mythic: Uses magic to enhance his covert methods to infiltrate other faiths (ChComp page 25)
Paladin: Uses magic to enhance his combat and leadership abilities (CL page 25)
Ranger: Uses magic to enhance his wilderness explorations (FRP page 98)

Mentalism:
Bard: Uses magic to enhance his music and knowledge (FRP page 100)
Magent: Uses magic to enhance his subterfuge and intelligence gathering (CL page 27)