Those're other comic companies. Other comic industries would be like Japan, Europe, and, uh, well that's about it. Other regions don't really have much of a comics market, they just get stuff from elsewhere. I know the Phantom is very popular in Australia and has his own long running comic there.
Anyway, here's the Market Share data for Feb 2007 for the top 20 companies in the US to give you an idea of what else is out there:
Publisher Comics, Magazines, & GNs Dollar Share Comics, Magazines, & GNs Unit Share
MARVEL COMICS 42.35% 47.38%
DC COMICS 32.80% 34.93%
DARK HORSE COMICS 4.26% 2.96%
IMAGE COMICS 2.75% 2.78%
TOKYOPOP 2.15% 0.91%
IDEA & DESIGN WORKS LLC 1.74% 1.52%
VIZ LLC 1.73% 0.85%
DYNAMIC FORCES 1.42% 1.64%
WIZARD ENTERTAINMENT 1.29% 0.90%
DEVILS DUE PUBLISHING 0.81% 0.75%
GEMSTONE PUBLISHING-MARYLAND 0.69% 0.17%
AVATAR PRESS INC 0.62% 0.47%
FANTAGRAPHICS BOOKS 0.46% 0.15%
RANDOM HOUSE 0.44% 0.16%
EAGLEMOSS PUBLICATIONS LTD 0.40% 0.13%
DIGITAL MANGA DISTRIBUTION 0.37% 0.12%
VIRGIN COMICS LLC 0.32% 0.41%
A. D. VISION 0.31% 0.12%
ARCHIE COMIC PUBLICATIONS 0.27% 0.43%
BONGO COMICS 0.25% 0.25%
Other Non-Top 20 4.59% 2.99%
other notable companies not on here (because they publish material sporadically) would be Top Shelf and Slave Labor. There's also several folded companies like CrossGen, Valiant, etc.