Burstsort4j contains an implementation of both the original Burstsort, which is quite fast but not particularly memory efficient, and the engineered Burstsort, which is extremely memory efficient and close to the speed of the original in most cases. Burstsort typically outperforms other string sorting algorithms for most data sets.
Both single-threaded and multi-threaded implementations are available, where the multi-threaded method will utilize all available processor cores using a simple thread pool executor. In this mode of operation, the buckets to be sorted are assigned to jobs and sorted in parallel.
In addition to Burstsort there is an implementation of the Funnelsort algorithm for sorting strings, which is faster than most string sorts but not as fast as Burstsort. Funnelsort uses string comparison while Burstsort is a form of radix sort and hence sorts only lexicographically by individual characters. The specific implementation of Funnelsort is modeled after the Lazy Funnelsort described by Brodal, Fagerberg, and Vinther. At the heart of the algorithm is an insertion d-way merger as described by Brodal and Moruz. Like Burstsort, the Funnelsort algorithm is cache- oblivious and thus typically performs well compared to algorithms that assume a unit-cost for RAM access (e.g. Quicksort).
Burstsort4j contains a Java implementation of the multikey quicksort algorithm. It takes a median of three approach to find the pivot, and delegates to insertion sort for small sublists. This sort is what Burstsort delegates to for sorting the buckets that hang from the trie structure.