Nikita Prokopov

Nikita Prokopov, known online as Niki or tonsky, is a Berlin-based programmer and designer best known as the creator of Fira Code, the open-source programming font with ligatures, and DataScript, an in-memory database and Datalog engine for Clojure and ClojureScript. Fira Code has more than 80,000 stars on GitHub, making it one of the most popular font projects ever published there.

Prokopov's own résumé describes more than two decades of work on distributed systems, highly interactive web apps and UI/UX design. Earlier career work included Java projects for industrial clients, a web framework for the Fantom language, and real-time data pipelines at Echo; his Habr profile lists Novosibirsk, Russia. In 2014 he started three projects that defined his public reputation: DataScript, the React wrapper Rum, and Fira Code, which extended Mozilla's Fira Mono with programming ligatures such as arrows and comparison operators.

Rather than build one company, Prokopov has built a body of independent work funded by consulting and sponsorship. He made AnyBar, a tiny macOS menubar indicator, co-authors Grumpy Website, a long-running blog cataloguing bad UI and UX, and consulted for products such as Roam Research (optimizing DataScript persistence), Fibery and Instant DB. Since 2020 he has been building a native desktop stack for the JVM: Skija, Java bindings for the Skia graphics library; JWM, a cross-platform window manager; and Humble UI, a Clojure UI framework built on both.

He also maintains Clojure Sublimed, a Clojure environment for Sublime Text, the Clojure+ standard-library extensions, clj-reload and Fast EDN, and in 2024 launched AlleKinos.de, a showtimes site covering cinemas across Germany. His blog at tonsky.me is widely shared for essays on software bloat, Unicode and UI design.

Prokopov matters to independent makers as a model of the sponsored open-source craftsman: one person whose free font sits in millions of code editors and whose libraries underpin commercial products, sustained by GitHub sponsors and consulting rather than a startup.