IS was a science fiction fanzine edited and published by Tom Collins.
Is was published in Austin, Texas, U.S.A. in the early 1970s. Six issues of IS appeared before the fanzine was renamed Apollo.
Issue 3 was released in July 1971, and featured the article "Tiptoeing Through Tulane" by Grant Carrington.
Issue 4 appeared in October 1971, and #5 in 1972.
Issue 6 was also published in 1972, and featured front cover art work by Cortén.
Issue 7 was released in 1975, and featured illustrations by Cortén.
Tom Collins later published the fanzine Transient.