[1] He has edited numerous prominent authors such as Vernor Vinge, Joan D. Vinge, Frederik Pohl, Andre Norton, Loren D. Estleman, Dan Simmons, Jack Williamson,[2] Timothy Zahn, Marie Jakober and Greg Bear.

He and his wife, author Joan D. Vinge lived in Madison, Wisconsin for many years, but have moved to Chapel Hill, North Carolina.

In 1968, Frenkel founded The Science Fiction Forum at the State University of New York at Stony Brook, a student-run organization which continues to operate a large lending library of science fiction, fantasy, and horror books.

[3] He also was the packager of The Year's Best Fantasy and Horror series edited by Ellen Datlow and Terri Windling (for sixteen years) and then Ellen Datlow and Kelly Link & Gavin J.

In July 2013, Frenkel left Tor after two complaints about sexual harassment at WisCon, a feminist science fiction convention where he had been a regular attendee and presenter, and (in 1994) a Guest of Honor.