Elixir
José Valim is the creator of Elixir. He is also co-founder of Plataformatec, a consultancy based in Brazil, a book author, and an active conference speaker.
C++
Jeremy is a full stack engineer, currently working on a company specializing in cross-platform real-time coordination and communication. He is a programming language and paradigm polyglot, with professional experience ranging from distributed systems and network protocols, to game engines and renderers for next-gen game consoles.
Erlang
Fred is the author of Learn You Some Erlang for Great Good!, a free online (also paid for, on paper) book designed to teach Erlang, as well as Erlang in Anger, a guide about how to be the Erlang medic in a time of war. He’s worked on writing and teaching training course material for Erlang Solutions Ltd, and on Real Time Bidding software for AdGear. He has since then moved to Heroku’s routing team, writing and maintaining large scale distributed systems in the cloud.
Clojure
Carin studied physics in college, and ended up as a software developer. Her passions led her to developing home automation and control libraries for drones. She helps lead the Cincinnati Functional Programmers and is a frequent conference speaker, keynoting OSCON and Strange Loop. To top it off Carin is the author of the upcoming book Living Clojure from O'Reilly.
Nim
Dennis is an active contributor to the Nim language while working on his Master's thesis at KIT. There he worked on research developing a new method for Regression Verification and teaching programming paradigms (Haskell, lambda calculus, type inference, Prolog, Scala, etc.). He also develops and runs DDNet, a unique cooperative 2D game.
Haskell
Chris is a long time FP and Lisp user who discovered a love of learning and types when he found Haskell. Aside from releasing multiple Haskell project, such as Bloodhound and Blacktip he took to teaching Haskell to spread the love and creating the Learn Haskell guide which he is turning into a book.
Go
Peter is a software engineer focusing on large-scale distributed systems. He's been writing Go since its public release in 2009, and is a huge fan of its simplicity and pragmatism. Peter lives in Berlin and works at SoundCloud, building the data systems and infrastructure that power the world's leading audio platform.
Ruby
Steve is a long time Rails core comitter and author of Designing with Hypermedia API's, Rust for Rubyists, and Rails 4 in Action. Currently Steve is providing his documentation expertise to Mozilla to improve and expand the Rust documentation.