liblfds is a portable, lock-free data structure library. Out-of-the-box ports are provided for Linux (user-mode) and Windows (user-mode and kernel-mode) on ARM, x86, and x64, under a variety of toolchains. Currently, the library contains a freelist, queue, ringbuffer, singly-linked list (logical delete only), and a stack. The homepage contains a blog, bugzilla, forum, and mediawiki. The mediawiki contains comprehensive documentation for development, building, testing, and porting. There is no license. You are free to use this code in any way.
Capsule Tree is a general purpose, self-balancing tree data structure for large, ordered data sets. It is designed to provide the same characteristics as B-trees and B+trees, but built from the ground up for in-memory usage. In other words, there are no provisions for “slow” I/O cases. The original motivation for this tree was a better backend for memory managers. However, the end result was a new sub-category of trees.