The AsyncArt Project is comprised by a set of Open-Source HDL libraries targeted to the efficient implementation of clockless/asynchronous circuits over Commercial-Off-The-Shelf FPGA devices.
It's worthy to note that, more than a standard library, the core of the AsyncArt project is a collection of very simple reference design examples that contain useful tricks and methodologies that can be easily applied to more complex projects.
In order to make easier the use of this techniques for educative & research purposes, the released reference designs has been standarized by porting them to a free to use project development environment.
For a full entry point to the AsyncArt project, visit the wiki pages.
Follow this link to access the reference design catalog