mentioned in this thread:<p>C<p>* Lua <a href="https://www.lua.org/source/" rel="nofollow noreferrer">https://www.lua.org/source/</a><p>* Redis <a href="https://github.com/redis/redis">https://github.com/redis/redis</a> (mentioned twice)<p>* Ruby <a href="https://github.com/ruby/ruby">https://github.com/ruby/ruby</a><p>* SQLite <a href="https://sqlite.org/src/dir?ci=trunk" rel="nofollow noreferrer">https://sqlite.org/src/dir?ci=trunk</a><p>C++<p>* Botan <a href="https://github.com/randombit/botan">https://github.com/randombit/botan</a><p>* ClickHouse <a href="https://github.com/ClickHouse/ClickHouse">https://github.com/ClickHouse/ClickHouse</a><p>Go<p>* Go's standard library <a href="https://cs.opensource.google/go/go" rel="nofollow noreferrer">https://cs.opensource.google/go/go</a><p>* HashiCorp repos, particular those by Mitchell <a href="https://github.com/hashicorp">https://github.com/hashicorp</a><p>F#<p>* jet.com repos <a href="https://github.com/jet?language=f%23">https://github.com/jet?language=f%23</a><p>Haskell<p>* Elm compiler <a href="https://github.com/elm/compiler">https://github.com/elm/compiler</a><p>Lisp<p>* CL-PPCRE <a href="https://github.com/edicl/cl-ppcre/">https://github.com/edicl/cl-ppcre/</a><p>* Mezzano USB driver <a href="https://github.com/froggey/Mezzano/blob/master/drivers/usb/mass-storage.lisp">https://github.com/froggey/Mezzano/blob/master/drivers/usb/m...</a><p>PHP<p>* Carbon <a href="https://github.com/briannesbitt/Carbon">https://github.com/briannesbitt/Carbon</a><p>* Laravel <a href="https://github.com/laravel/laravel">https://github.com/laravel/laravel</a><p>Python<p>* pytudes (notebooks) <a href="https://github.com/norvig/pytudes">https://github.com/norvig/pytudes</a><p>R<p>* sf (ex of functional OOP) <a href="https://github.com/r-spatial/sf">https://github.com/r-spatial/sf</a><p>Ruby<p>* Sequel <a href="https://github.com/jeremyevans/sequel/">https://github.com/jeremyevans/sequel/</a><p>* Sidekiq <a href="https://github.com/sidekiq/sidekiq">https://github.com/sidekiq/sidekiq</a><p>Rust<p>* ripgrep <a href="https://github.com/BurntSushi/ripgrep">https://github.com/BurntSushi/ripgrep</a><p>Scala<p>* fs2 (ex of good type safety) <a href="https://github.com/typelevel/fs2">https://github.com/typelevel/fs2</a><p>* monix (ex of ugly code with great performance) <a href="https://github.com/monix/monix">https://github.com/monix/monix</a><p>TypeScript<p>* GitHub Desktop (ex of SPA) <a href="https://github.com/desktop/desktop">https://github.com/desktop/desktop</a><p>---<p>thanks to: cejast, bb86754, wewxjfq, antonyt, bit, diego_moita, agjmills, freedomben, Contortion, valenterry, DethNinja, mberning, seneca