Fireworld, suggested that "hacking his Facebook account" and seeing if he had visited gay websites could confirm a parent's suspicions.
The company has since taken down the article after a French youth LGBT rights group highlighted it.
L'Amicale des jeunes du Refuge's thread about Fireworld's article was retweeted by French Secretary of State for Equality Marlène Schiappa, who wrote that it showed that "homophobia and sexism have their roots in the same gender stereotypes. We will fight them together".
Fireworld’s article insisted that family was fundamental. “That's why the sexual orientation of your children, directly responsible for the continuation of your family, is very important to you.”
The article went on to list the clues that might cause a parent to suspect that their son might be gay. The article makes no mention of female homosexuality, we guess it is because conservatives, like Queen Victoria, do not believe it exists, or if it does it is rather hot.
The software spots clues that your son might be gay which are so laughable as to indicate that they do not really understand what homosexuality is all about.
Apparently if your son “takes good care of himself", is more interested in reading and theatre than in football, is shy, has certain piercings and likes female singers he is clearly a homosexual.
It then suggested a variety of ways to be sure, including "monitoring his Facebook use", seeing "if he has visited gay forums" and "spying on his private messages".
Fireworld wrote that "the article had the sole aim of improving search engine optimisation and was never intended to be read by humans" - fair enough we tend to think that queer bashers are not human either.
"We regret not having reflected on the consequences of this type of content..." the firm emailed. "We sincerely apologise to all those who may have felt offended by this content," the company added.
However, the English language version of Fireworld's site suggests a range of scenarios in which a potential customer might want to monitor someone else's computer, including "control your teenage offspring's PC", checking "what your employees are doing" and "detecting infidelity in your marriage or relationship".
It is not legal in France to install spyware on someone else's computer to monitor it, without their knowledge.
Fireworld points out to customers that they must comply with the law when using their products. However, it says, "installing [its product] to make sure that your children are not endangering themselves on the Internet or on social networks, come[s] closer to being legal".
French newspaper Liberation reports that spyware vendors are usually more subtle in their claims for their products, as French law does not allow advertising which incentivises the illegal use of such tools.