Barbara Bratzel is a science teacher at the Shady Hill School, a PreK-8 independent school in Cambridge, Massachusetts. In addition, she is a consulting teacher at the Center for Engineering Education and Outreach at Tufts University. Her most recent book, STEM by Design, a collection of classroom activities using the LEGO EV3, was published in February 2014.

Michael duPont is a maker, pilot, and theatre technician based in Central Florida. He recently graduated from Centre College in Danville, Kentucky. His specialties include microcontrollers such as the Raspberry Pi and Arduino, robotics, wearables, and other small electronics. You can find many of his open source projects on GitHub and on his website (http://mdupont.com/).

Jeroen Hartsuiker (born in 1971) played with LEGO Technic until his early teens. His dark ages (time when a person stops collecting and using the Danish bricks) ended while visiting LEGOLAND Billund in 1998, when he attended a workshop exploring the first generation of the MINDSTORMS Robotics Invention System. Since then, he has owned and used every generation of the LEGO robot, and he wrote courseware and delivered a presentation on how to control the MINDSTORMS NXT robot using Microsoft® Robotics Developer Studio. He occasionally contributes a module to the Great Ball Contraption (GBC) at LEGO WORLD in the Netherlands. Furthermore, a MINDSTORMS robot is sometimes used to make the software-development classes he teaches even more interesting. You can visit his blog at www.dotnetjes.nl.

David Lechner works mostly as a freelance computer programmer and occasionally as a "Mad Scientist" teaching robotics as an after-school program in elementary schools. He also just completed his rookie year, coaching a FIRST LEGO League team, and has devoted much of his time to reverse engineering the EV3 as a core contributor to the ev3dev project. Prior to being self-employed, he spent 8 years doing industrial automation in the water and wastewater industry. He has a bachelor's degree in electrical and computer engineering from Oklahoma State University.

Diego "Kartones" Muñoz, more commonly known by his nickname, Kartones, is a multidisciplinary developer who lives in Madrid, Spain. Having worked for more than 12 years with all kinds of desktop, mobile, and web applications, he has used quite a few languages such as C++, C#, PHP, and more recently, Ruby and JavaScript.

Regarding LEGO MINDSTORMS, he fell in love with RCX and then the NXT, both of which he liked to code in C instead of the default firmware and brick system. Now, with MINDSTORMS EV3, he seeks to code robot logic in Node.js. He's also been a technical reviewer for LEGO Mindstorms EV3 Essentials, Packt Publishing.

He loves learning about anything he comes across and keeps a few blogs. He sometimes speaks at events or user groups, and he would love to do more open source work. He can be reached at http://portfolio.kartones.net.

Geoff Shannon has been an enthusiastic hardware hacker from a young age; his first job was building automated production equipment with Provel Inc. He has a bachelor's degree in computer science and recently attended a batch at Hacker School in New York City. In late 2013, he started working with LEGO robots by exploring the leJOS project and using it to run a Clojure REPL on his EV3. He currently lives in Seattle, WA, working as a software engineer.

To see what Geoff is currently working on and thinking about, check out his blog at www.zephyrizing.net. You can also follow him on Twitter at @RadicalZephyr.