fxL

fxL is a multi-paradigm programming language and runtime designed for concise, safe, and high-performance scripting and data-processing tasks. The name fxL is an acronym commonly expanded as functional expression language, reflecting its emphasis on expressive, function-rich code. It was developed by the FXLab project starting in the mid-2010s, with stable releases around 2017 and subsequent adoption in the early 2020s. The language targets both traditional desktop/server environments and web deployment via WebAssembly.

The core design goals are safety, composability, and efficiency. fxL features a statically-typed system with type inference, algebraic data types, and pattern matching, enabling concise yet predictable code. Functions are first-class, and the language supports higher-order programming, modules, and separate compilation. Its concurrency model combines lightweight green threads with a message-passing runtime, aiming for scalable I/O-bound workloads. Null safety and immutable-by-default data are common defaults.

fxL programs run on the FXVM virtual machine and can be compiled to WebAssembly for browser or edge execution. The language provides an extensive standard library for I/O, networking, data processing, and interoperation via a foreign function interface with C and JavaScript when targeting non-native runtimes. Tooling includes a compiler, an interactive REPL, a package manager, and IDE integrations.

Since its introduction, fxL has seen varied adoption in research and industry projects that require rapid data handling and scripting with strong type guarantees. See also: list of programming languages, FXLab project.