The Wikipedia Game tries to find a path between any two wikipedia articles. It uses a modified breadth-first search and expands the first 10 unique child articles on each article it explores. This algorithm will explore at most 1000 articles before calling it quits :).
Coming soon: iterative-deepening depth-first search, improving memory-efficiency, and customizing how many child nodes to explore for each article.
This service only works with Wikipedia articles in English Wikipedia. URL format should be https://en.wikipedia.org/wiki/...
Examples
Start Article: https://en.wikipedia.org/wiki/Bo%C3%B6tes_void Bootes Void
End Article: https://en.wikipedia.org/wiki/Mariana_Trench Mariana Trench