This is actually a sort of misnamed rule. In 1694, John Bernoulli decided to work for his former student l'Hopital to solve problems for him and keep him generally up to date on various advancements in Calculus. One of the problems that l'Hopital gave him was the indeterminate form problem, which Bernoulli solved as promised. Later, l'Hopital published his notes on calculus in a book and the rule for solving limits with indeterminate forms was part of it. Now, l'Hopital wasn't such a bad guy, he did acknowledge his debt to Bernoulli and even published the book anonymously so he wouldn't claim ownership. Despite this, Bernoulli went nuts, accusing l'Hopital of plagiarism. Unfortunately, this accusation was inadvertently supported after l'Hopital's death in 1704 by the publisher's promotion of the book as l'Hopital's. Quite famous as a jealous man, Bernoulli insisted that he was the author of the entire work. History accepted Bernoulli's claim (until recently), but still named the rule after l'Hopital.