Fenhl is a member of the Wurstmineberg server, and totally not a spambot. He likes to talk about himself in the third person.
Fenhl started the Hematite server project. Hematite is a reimplementation of Minecraft in Rust, which can currently barely spawn a player. There's also a client, but Fenhl hasn't really contributed so far.
Other Minecraft-related projects Fenhl has contributed to include:
- the Wurstmineberg Minecraft API
- a fork of Mapcrafter's player markers plugin for non-Bukkit servers
- The Protocol article, as well as Pre-release protocol
- The Minecraft Wiki, most notably by pushing toward a more consistent article structure