Meet 13 companies that are part of the Winter 2018 batch of Y Combinator. (You can see more companies from the YC W18 batch here, here, here, here and here.)

Anjuna creates a software security perimeter around an application, which provides hardware-grade protection and removes the need to secure or patch the host machine. Anjuna’s solution doesn’t require any code changes and is the ideal and the simplest solution for vulnerabilities like we saw with Meltdown and breaches like the Target hack. Anjuna has raised over $3mm from investors including Playground, Data Collective, Founder Collective and David Ulevitch (founder of OpenDNS).

Runa HR is an automated payroll company built for SMBs in Latin America (3X larger SMB market than the U.S.). Think Gusto for Latin America. Runa has raised over $1 million from investors including Nubank (fastest-growing bank in Brazil), execs at Cabify, Rappi, WeWork and Salesforce Ventures.

Modern Health is the first emotional health benefits platform that supports all employees. 68% of employers report mental health issues (up from 55% in the past year). Most employers use Employee Assistance Programs (EAPs), which is a $5.1B market, and only 1-3% of employees actually use them and the people who really need help aren’t getting it. Modern Health lowers the barriers to support by identifying an employee’s needs and connecting them to the appropriate care (e.g., therapy, specific meditations, career coaching, etc.) Modern Health has seen an average of 25% employee engagement with their platform, which is 8-10x the industry average.

Founded by a team of UK athletes, LetsDoThis.com is booking.com for endurance events. Whether you’re running your first 5k fun run or your tenth ultra triathlon, it is the best place to find your perfect race. Races are the new religion; they’re what we spend our Sunday mornings doing now. The big race companies like Spartan, ToughMudder and IronMan are listing on the site, and the founding team includes an Olympic gold medalist.

OpenSea is the first (and largest) peer-to-peer marketplace for cryptogoods (like Ebay for crypto assets), which include collectibles, gaming items, and other virtual goods backed by a blockchain. On OpenSea, anyone can buy or sell these items through a smart contract. Over the last month, as the number of games in the space continues to increase, OpenSea has seen around half a million dollars in volume.

Edwin.ai is an English as a Foreign Language (EFL) service powered by AI and delivered by bots, voice assistants, and professional human instructors. It combines effective pedagogical content and the latest technology with on-demand human instructors to offer affordable, personalized 1:1 tutoring to students studying for standardized EFL tests. It aims to disrupt a $40 billion USD market by preparing students for the tests in ⅓ of the time at ⅓ of the cost of private tutoring. Its initial focus is on the Japanese, Korean, and Spanish-speaking markets. The company’s first paid product, which has been tested by 700,000 students, trains students for TOEFL, a widely accepted English language proficiency exam. Additional preparation courses will be released later this year.

TrapFi makes it easy for freelance developers to get paid per pull request. Freelance developers earn an average $90K per year, most of which is paid out weeks and months after the work is completed. TrapFi lets developers generate the client agreement and links directly with Github (and others), so when the developer submits their work, TrapFi triggers a real-time payout from the client. It’s kind of like Uber Instant Pay but for software developers.

Macromoltek does computational drug discovery for pharma companies, focusing on antibodies for therapeutics and diagnostics. This mother-daughter team’s approach aims to make research for everything from flu to cancer treatments an order of magnitude faster. With an accelerated process to discover antibodies, medical researchers can (1) craft targeted treatment plans for previously undruggable targets and (2) overcome patients’ drug resistance, a major challenge when treating diseases caused by bacteria, viruses, and parasites. Read More about Macromoltek in VentureBeat.

NexGenT, founded by two former Air Force IT instructors who’ve trained over 1000+ engineers for the U.S. Military, provides real world IT Engineer training that makes students job-ready (for IT Ops roles like Network / Systems Engineer) in months instead of years, and without the typical student debt from traditional institutions. NexGenT is now launching a new Tech Degree program with its first Cohort beginning in May of 2018. In this program NexGenT guarantees that tuition will be reimbursed if the students are unable to land a job after their training. Read more about NexGenT in TechCrunch.

Vena Medical is making a tiny camera that goes inside veins and arteries to help physicians navigate around the body. Using the latest advancements in fiberoptic technology, this new method of navigation will expand the candidate pool for intravascular procedures by hundreds of thousands of patients per year.

Repl.it lets you start coding in your favorite programming language in 2 seconds; it lets you build and deploy apps right from your browser. So many people love what they’re building that they’re likely to hit a million monthly active users by Demo Day. The founders wanted to build something to solve their own problem — back in school they were tired of setting up their development environment on every machine they wanted to code on, and they dreamed of a world where you could just open a tab in the browser and start working. They built Repl.it to give developers access to simple, powerful tools and a community of hackers, aspiring programmers and teachers. They make it possible to learn, practice and build, all in the same place. Read more about Repl.it in TechCrunch.

EasyEmail is a Gmail plug-in that helps you compose emails quickly. We train our software with your inbox and quickly suggest what you should write based on your previous responses. Read more about EasyEmail in TechCrunch.

YouTeam is a marketplace for hiring tech talent from software development shops. Great engineers are in huge demand, but in-house hires are expensive and freelancers aren’t always suitable for long term work. YouTeam uses a source of 5 million engineers that everyone else overlooked. Unlike many freelancer marketplaces, YouTeam’s engineers work for dev shops and are usually not available for hire as individual specialists. On YouTeam, companies can rent the services of these engineers directly without having to deal with the sales teams of their employers. Shops list their engineers; clients find and engage with them directly through the website. The process is as simple as when you hire a freelancer but as secure as if you were hiring in-house.