Structurally, Alexandrian Wicca is close to Gardnerian: a coven led by a High Priestess and High Priest, three degrees of initiation, oathbound material, seasonal festivals and lunar workings. Only a second-degree initiate may initiate, and only a third may elevate another to the third. Some covens add a probationary rank before the first degree, which the parent tradition does not.
In practice the two are close enough that many covens work both lines, and cross-initiation between them is common, a further indication of where Alexandrian Wicca actually came from. The differences that remain are of emphasis: more ceremonial magic, a somewhat more flexible attitude to the received text, and less insistence on secrecy about the fact of the tradition's existence.
Its wider spread owes most to two of its initiates. Janet and Stewart Farrar published Eight Sabbats for Witches in 1981 and The Witches' Way in 1984, and between them these books printed a very large quantity of working ritual material that had previously circulated only by hand-copying. Traditionalists in both lines regarded that as a breach. It is also the main reason the Alexandrian corpus is the one most widely available to people who never met an initiate, and the reason a great deal of eclectic Wiccan practice is Alexandrian in its bones without knowing it.
Maxine Sanders continued to teach for decades after the marriage ended and after Alex Sanders' death in 1988, and is generally credited with the tradition's survival as a serious body of practice rather than as a press story.