These projects are unofficial contributions for LEMON. Most of them are unmaintained.
Bidirectional Dijkstra, A*, and bidirectional A* algorithms for LEMON (by Tamas Bibok).
AVL and Red-Black Tree implementations for LEMON (by Zsolt Dollenstein).
Simple random graph generators for LEMON.
Unsplittable Multicommodity Flow Algorithms for LEMON 0.x (by Zoltan Bojas).
KDE Graph Widget and Application for LEMON 1.x.
A Perl language binding for LEMON 0.x.
Routing algorithms in telecommunication networks based on LEMON 0.x.
A graph library for C#, inspired by LEMON.
The following tickets contain implementations of various extensions for LEMON, which have not been merged to the main development branch yet.