These are various projects that I have made small contributions to.
The Computer Language Benchmarks Game
A site devoted to hosting benchmarks of algorithms in a variety of languages. I provided an improvement to the C++ implementation of the n-body benchmark, making it as fast as any implementation in any language.
A widely used set of C++ libraries. I provided patches to implement symlinks for the filesystem library.
A set of ergonomic keybindings for Emacs. I fixed a number of bugs and radically sped up loading.