There are 2 repositories under reference-counting topic.
GCC plugin that embeds CPython inside the compiler
Safe concurrency in D (`shared` made easier)
garbage collector algorithm 垃圾回收算法的系列实现
An object-oriented, extensible reference-counting utility for Fortran
A fast reference counting library for C++
GCC plugin for C language that tracks references to allocated objects
Intrusive reference counting smart pointer, highly configurable reference counted base class and various adapters
Reference counted fortran data structures
A multithreaded concurrent GC with industrial-strength object-dissolving action
A Pascal stream class that is implemented as an interface, thus offering reference-counting.
An Arc (atomically reference counted smart pointer) that supports customized dropping strategies using Backdrop.
Persistent tree structure written in Pascal that can handle binary data.
An implementation of an ANSI C class system similar to Apple's Core Foundation. (Retain/release, autorelease, mutable/immutable, etc)
C# library for managing shared ownership of Disposable reosources
Manage C++ Objects's lifetime accessed through a C API
Wrangle class names on HTML elements with reference counting.