Emellie O'Brien sorts trash for a living on movie and television sets--but, no, she's not a garbage collector. She's the founder of Brooklyn-based startup Earth Angel, which helps productions become more sustainable by educating crews on best practices, using eco-friendly products on set, minimizing waste, and tracking carbon footprint usage. By adopting these practices, 29-year-old O'Brien says, productions can save $60,000 to $100,000 on waste bills and make a lasting impact. For instance, a scene from The Amazing Spider-Man 2 was shot in an area that was destroyed by Hurricane Sandy. Her efforts lead to the production crew planting new trees and fixing up the public benches for the scene. (The producers saved about $400,000 incorporating sustainable practices, according to O'Brien.) The four-employee startup, founded in 2015, "greens" about 10 productions annually. Earth Angel generated $250,000 in revenue last year, she says. While O'Brien admits the company is targeting a niche market, it has worked with some of the biggest names in the industry: Director Darren Aronofsky employed her for movies like Noah--even tweeting out her sustainability reports. Earth Angel also worked on the sets of blockbuster films like Black Panther, Ghostbusters, and The Avengers. --Michelle Cheng

More and more Americans are opting for cremation--so much so that it recently surpassed the number of annual burials. With her startup, Adelle Archer proposes a unique next step for honoring the deceased: turning their ashes into diamonds. Human remains contain carbon, which is the key element to creating the precious stones. Eterneva takes a portion of those ashes and, through partnerships with a diamond-growing lab in Amsterdam and cutters in Antwerp, turns them into a piece of jewelry. Customers can pick their design and color to best commemorate a loved one. The company stays in frequent contact with them throughout the eight-month process, providing monthly updates and, whenever possible, hand delivering the finished product. Archer sees the company as changing people's relationship with loss--and helping to eternalize their loved ones. "A diamond lasts more than a single generation," Archer says, "the way an urn of ashes won't." --Kevin J. Ryan

Cellular agriculture--the production of food and other goods from cells cultured in a lab or factory--has the potential to transform the world's food systems. That can't happen fast enough when it comes to the oceans, where virtually every major fishery is dangerously overexploited, according to the U.N. Food and Agriculture Organization. After studying biochemistry at the University of Massachusetts-Amherst and working as cancer researchers at hospitals in New York City, Mike Selden and Brian Wyrwas got the idea to bring emerging cell-ag techniques to bear on this problem. They relocated to the San Francisco Bay Area and enrolled in IndieBio, an accelerator for biotech startups. In September 2017, they finally got to taste the first fruits of their labors: carp croquettes whose main ingredient was cultured from stem cells. By the end of 2019, they hope to have a commercially available product consisting of fish cells bound together by food enzymes. Selden says it will be "a lot like the tuna mash for a spicy tuna roll. It's still fish. It's just fish cells that aren't in the shape people are used to having them in." The latter, something more akin to a fish fillet, requires more sophisticated tissue engineering and is likely two years off, he says. --Jeff Bercovici

While working at a software company in her early 20s, Mathilde Collin had a realization. Every type of software she could think of had evolved in some way over the previous decade, except for the one she and her co-workers used the most: email. In 2013, she took that notion to European startup studio eFounders, where she met fellow Parisian Laurent Perrin. Just months later, the French duo co-founded Front, a San Francisco-based software company that has amassed $79 million of funding in less than five years and tripled its revenue every year since 2014.

Collin and Perrin define Front as a "shared inbox for teams"--a modernized version of email that pulls disparate communication channels like Outlook, Slack, Salesforce, social media, and text messages into one platform. Managers can assign employees to handle specific conversations without the hassle of cc's and bcc's, and teams can group-edit messages in real time before they're sent. Collin believes Front can affect a fundamental part of modern life--after all, everyone uses email. "We have an entry point to deeply change how people work," she says, before pausing to acknowledge, "It's an incredibly ambitious thing to do." --Cameron Albert-Deitch

As teenagers in the Netherlands, Jobert Abma and Michiel Prins hacked into the high school TV station. When they were in college, they told an education software company that its platform leaked grades and personal data. In 2012, Alex Rice, then Facebook’s head of product security, challenged them to find a vulnerability. They did, scored a contract with Facebook, and started hacking into Twitter, Spotify, and Uber to win work from them, too. Along with Merijn Terheggen and Rice, they started HackerOne in 2012, to run “bug bounty” programs--which reward hackers for finding security flaws--for Starbucks, GM, Uber, the U.S. Department of Defense, and about 1,000 other organizations. Such customers pay subscriptions, costing from the low four figures to tens of thousands per year. --Will Yakowicz