- Matheus Moreira built Lone Lisp, a programming language implemented directly on Linux system calls without using the C library, as a personal project to prove that freestanding C programming is viable.
- His interest in computing began with video games (Mega Man Battle Network), leading him to learn English via forums and start programming with C++ at age 13-14 in a Brazilian technical school.
- He learned multiple languages (Java, Ruby, Python) out of curiosity and a search for a 'language to call home', eventually settling on Ruby and C, inspired by low-level simplicity and kernel source code exploration.
- Freestanding C (without libc) removes warts like global state (errno, locale, strtok) and legacy code, allowing cleaner programming; he created 'liblinux' for system call wrappers but later archived it after discovering Linux's nolibc.h.
- Lone Lisp features a minimal design with freestanding C, providing system call primitives, generators, delimited continuations, and a restartable condition system built on continuations, all within a Lisp evaluator that avoids bytecode compilation.
- The language uses only a small fraction of Linux's 300+ system calls (e.g., execve, mmap, openat) and excels in startup speed, though it's 10-100x slower than Python due to its list-level interpreter approach.
- Performance improvements are planned via JIT compilation (mmaping executable pages) or precomputing hash tables, while he uses AI (Claude) for code review and project management to manage the unbounded development scope.
- Matheus chose medicine as his career (doctor since 2019) but continues programming as a hobby, aiming to reinvent Linux userspace tools (shell, static site generator) with Lone Lisp and inspire others to take radical ownership of their computing stacks.