This page offers PGN files containing all the reciprocal zugzwang positions (Black to move loses, White to move cannot win) with up to six men, and all the "squeeze" positions (White wins with or without the move, but the win with White to move takes at least three moves longer than that with Black to move) apart from those with five men against one.

The following files are offered:

readme.pdf
describing the material offered in greater detail;

zug3456.zip
containing the reciprocal zugzwangs;

sqz345.zip
containing the squeeze positions with up to five men;

sqz2v4.zip
containing the squeeze positions with two men against four;

sqz3v3.zip
containing the squeeze positions with three men against three; and

sqz4v2.zip
containing the squeeze positions with four men against two.