LEcount is a software for counting linear extensions of partially ordered sets (posets). It includes a collection of algorithms, which are documented in the paper *Counting linear extensions of sparse posets* (IJCAI'16). LEcount and the posets used in the empirical evaluation of the algorithms are available for download:

LEcount is written in C++ and currently requires the GNU C++ compiler (G++) and the GMP and Boost libraries. The current version contains cursory instructions for running each algorithm presented in the paper (see readme.txt).

The posets are named as follows:

- avgdeg_
*n*_*k*: Posets on*n*elements of average degree*k*. - maxindeg_
*n*_*k*: Posets on*n*elements of maximum in-degree*k*. - bipartite_
*n*_*p*: Bipartite posets on*n+n*elements of average density*p*. - gridtree_
*n*_*t*: Grid tree posets on*n*elements of treewidth*t*.

Each poset is represented as a 0-1 matrix, where a 1 at [i,j] indicates i < j.