Interlocking

Hedgehog
Hedgehog Burr
Helix the Burr
Hellas Cube
Hermaphroditic Blocks
Hermit Cube
Hex Screws!
Hexator
Hog Wild 1
Hog Wild 2
Holey Cross
Hollow Burr
Hollow Cube 2
Hook Cube
Hooker Cube
Hummingbird
Hunos
Hybrid (Altekruse 14)
Hydra
Ice Cube