What is l2c?

L2C is a compiler that turns a strict, typed subset of the Lua programming language into native C code with no garbage collector. It is built for two very different but equally demanding worlds: high frequency trading systems, where even a tiny pause to clean up memory can cost money, and small embedded devices like the Raspberry Pi Pico or ESP32, where there is barely any memory to spare in the first place. The core idea is that Lua's friendly, script like syntax is easy to write, but its usual garbage collector introduces unpredictable pauses. L2C removes that garbage collector entirely and forces the programmer to use fixed, pre-allocated blocks of memory instead. It supports things like fixed size buffers, a pool of memory that can be instantly reset between processing steps, and direct ways to read raw bytes as structured data without the usual conversion overhead. In exchange for this control, L2C deliberately refuses to support features that need a garbage collector, such as joining strings on the fly, flexible dictionaries, closures that capture variables, or coroutines. The project also ships a small standard library of ready made connectors to popular C and C++ tools, covering fast networking, lightweight databases, JSON parsing, asynchronous event loops, and bare metal operating systems for microcontrollers. To build a program, developers write their logic in this typed Lua subset, then use Docker based build environments to compile it into either a small standalone program for a regular computer or firmware for a microcontroller. This is a niche, opinionated tool aimed squarely at experienced systems programmers working on trading software or embedded firmware who want Lua's simpler syntax without giving up the speed and predictability of hand written C. It is not meant as a general purpose Lua compiler, and the maintainer states plainly that requests to add garbage collection support will not be accepted.