Manliness, metaphorically embodied these days by facial hair, grilling meat and building domestic "man caves," is now carving its own space online.

Look around. The line of what is and isn't masculine is blurring, whether it is through manscaping, as shown in Morgan Spurlock's new documentary "Mansome" or barbecue chefs such as Elizabeth Karmel expertly wielding tongs.

This trend may be rightly celebrated for breaking gender stereotypes. But as the "mantuary" for hanging with the bros gets invaded by scented candles, some entrepreneurs are fighting back with new websites that cater to stereotypically manly interests such as cars, sports, tech toys and bachelor living.

They have names such as Dudepins, Manteresting, PunchPin, Gentlemint and Dartitup, and they claim to target the male demographic not just in content but also in utilization. They've all launched in the past six months, and their inspiration appears to be the skyrocketing popularity of Pinterest, a virtual pinboard where users post, or "pin," images of their favorite things.

Unlike Pinterest, however, these sites have fewer photos of wedding dresses and more pics of beards, babes, guns, Harleys and bottles of whiskey.

Pinterest has more than 20 million users, and a survey last spring found they spend more time there per month than users of any other social network except Tumblr and Facebook. Considering those numbers, and that Pinterest has been valued at $1.5 billion, and it's no surprise that similar websites such as Pinspire, Clipix and Stylepin have popped up.

But Pinterest and its copycat sites are largely populated by women. A February survey by Visual.ly found that women comprise 83 percent of Pinterest users. A quick browse through its most popular pins and its About section ("People use pinboards to plan their weddings, decorate their homes and organize their favorite recipes") seems to reinforce this gender imbalance.

Brandon Harris, co-founder of Dartitup, said that when he first played around with his fiancee's Pinterest account, he appreciated the concept.

"I loved what it did and I loved the features, but I didn't like the content," he said. "The content is not geared towards a guy. I am not interested in cupcakes or puppies. But I am interested in cars and gadgets."

Not that there aren't any men pinning. But Ricardo Poupada, co-founder of AskMen, said that when his online men's magazine started using Pinterest, they noticed that there wasn't a strong male presence. "There's still that perception that it is a female-centric site," he said.

'Manly' alternatives

Enter sites such as Manteresting.

"We were thinking of mimicking the (Pinterest) business concept but catering to the male demographic," said Brandon Patchin, who co-founded Manteresting with Jesse Michelsen. "Jesse and I, we are intentional in our naming of our website. We needed to be divisive."

While Manteresting has managed to rack up more than 2 million page views since it started in February, the plan is not to declare war against Pinterest, Patchin said.

So what makes up a manly image bookmarking website?

Let's start with the look. Manteresting's layout swaps Pinterest's cursive red title on a cream background with a black, block-letter title and the tag "Interesting.Man.Things" on a dark steel background. Dartitup goes for a dark navy blue with white lettering, and Gentlemint opts for an elegant black-and-white theme with a moustachioed logo.

Then there's the testosterone-laden choice of words. Instead of "Pin It," users on these websites can "Nail It" (Manteresting), "Dart It" (Dartitup) and "Save to Your Mint" (Gentlemint). Dudepins' slogans are "Dudes like sharing stuff" and "Man Up. Sign Up. Pin Up."

The founders of Manteresting, Dartitup and Gentlemint were all quick to say that they don't emphasize photos of women in bikinis or tolerate offensive content. Their most popular image subjects range from food to technology to sports to memes to bachelor pads, they said.

Embracing stereotypes?

Glen Stansberry, co-founder of Gentlemint -- "a mint of manly things" -- said he felt no pressure to set a certain bar for manliness.