zsort is a library that I started working on as a simple hobby project. More or less around the same time I decided to check which algorithms the different Common Lisp implementations use. It is now part of Quicklisp so it can be easily used (thanks Zack!).
The main goal of zsort is to be a collection of portable sorting algorithms. If they can be fast, even better. Common lisp provides the sort and stable-sort functions but these can have different algorithms implemented according to each implementation, which can make an application unportable if you rely on a specific type of sorting. Also, the standard functions might not be the best for a certain situation and as such you might need a specialized sort. Even if for most situations the standard functions are more than enough, the zsort library could be a useful complement.
Right now the implemented algorithms are: insertion sort, quicksort, randomized quicksort, merge sort, heapsort and counting sort. The plan is to add more algorithms, for example, bucket sort and timsort. However, the main thing on the todo list is adding the possibility of external sorting (to handle large amounts of data) and parallel versions of some sorting algorithms. I am considering using lparallel for this but I am still undecided.
There is still a lot of work to be done, but I think the library as it is can already be a little useful. And of course, all kind of suggestions and improvements are welcome!