I made my first Free Software contribution in 2003 and have been contributing to Free/Libre Software since that time.

Some of my projects:

Parenscript

Translator from an extended subset of Common Lisp to JavaScript.

CLiki2

Andrey Moskvitin and I wrote the second (current) version of CLiki, the Common Lisp Free Software wiki.

uri-template

Common Lisp implementation of the URI Template proposed standard draft version 01 as a reader macro that does both templating and destructuring.

vas-string-metrics

Jaro, Jaro-Winkler, Soerensen-Dice, Levenshtein, and normalized Levenshtein string distance/similarity metrics algorithms.

vas-radix-tree

Radix tree implementation for Common Lisp sequences.

vas-sparse-vector

Sparse vectors for Common Lisp.

RCscope

Modern Cscope Emacs interface.

Eager Future2

Composable futures library (concurrent/parallel programming).

Vacietis

C to portable Common Lisp compiler. A single-pass C preprocessor/tokenizer/parser is implemented as a Common Lisp reader macro. The resulting AST is also suitable for use in C-to-C code transformation tools. Memory allocation is done using typed arrays, and pointers are represented as closures. A libc implementation (ongoing) in portable Common Lisp is included.

In addition, I have contributed improvements and bug fixes to dozens of other Free Software projects.