The definitive reference work on science fiction is coming back for the first time in 18 years -- and it's going online.

The third edition of The Encyclopedia of Science Fiction will be released later this year and will be more than double the size of the last edition from 1993, with the beta version carrying some 3 million words, 12,000 entries and 100,000-plus links, the UK's Orion Publishing Group announced today.

The free encyclopedia will be posted at www.sf-encylopedia.com and released by ESF, Ltd. in collaboration with Victor Gollancz -- Orion's science fiction and fantasy imprint -- to coincide with Gollancz's 50th anniversary as a sci-fi publisher.

We're delighted to have been able to facilitate the online publication of this monumental and definitive work -- more than ever the single, reliable reference source which anyone interested in SF needs, Orion Deputy CEO and Group Publisher Malcolm Edwards said in a press release. As a contributing editor to that long-ago first edition, it's a particular pleasure to me to have been able to play a part in making this happen.

Two of the primary editors of the encyclopedia are also returning for the new effort: Peter Nicholls and John Clute.

Nicholls, who founded the encyclopedia, edited the first edition in 1979, and edited the second work with Clute, returns as editor emeritus. And Clute is again one of the lead editors, this time with David Langford. Graham Sleight is managing editor.

The two previous editions of the encyclopedia both won a Hugo Award, science fiction's most prestigious honor, in the nonfiction book category.

Orion said the coming encyclopedia will cover every area of science fiction, including authors, illustrators, movies, music, games, and fanzines. Three-quarters of the content will be unveiled in the beta version, with the text to be completed through monthly additions by the end of 2012.

Early fan responses have been enthusiastic.

Hurrah!!! Coming soon, the third edition of this remarkable reference work, online, searchable, free, Eileen Gunn wrote on Twitter.

Edward B. Colby is the Books editor of the International Business Times. He can be reached at e.colby@ibtimes.com.