Do u eat NON-Halal meat?

Kosher is allowed. I remember one of my coworkers was a strict Jew and would not eat anything but Kosher meat. During work lunches and dinners, he and I would be the only ones ordering something vegetarian while the rest indulged in their meat/pork/whatever. That really surprised me because I didn't know some Jews were also so cautious about eating the allowed stuff like we Muslims are.