From the publisher:

A concise, comprehensive collection of magic spells for use with the "original edition" fantasy game rules (as published by Gygax & Arneson, 1974-1975). A handy supplement for both DMs and players of wizard characters.

Personally, we always wished that the magic spells were set aside in their own booklet (instead of filling up the basic player's book), and now we have that. It uses the OGL to extract the bare-bones original rules back out of current, freely available source material.

All the first level spells fit on a single page, and some spells are house ruled based on the author's experience with the game.