Tomas Petricek discovered functional programming as a graduate student at Charles University in Prague. He has been a Microsoft C# MVP since 2004 and is one of the most active members in the F# community. In addition to his work with F#, he has been using C# 3.0 in a functional way since the early previews in 2005. He interned with the F# team at Microsoft Research, and he has developed a client/server web framework for F# called F# WebTools. His articles on functional programming in .NET and various other topics can be found at his web site tomasp.net.
Jon Skeet is a Senior Software Engineer at Google, working in London. He has been involved in the C# community since 2002, initially in newsgroups, then through his blog, user groups, international conferences and the Stack Overflow Q&A site. Jon enjoys putting the language through its paces, finding new and interesting ways to use and abuse it.