Matyas–Meyer–Oseas
A recipe for turning a block cipher into a one-way compression function: the chaining value becomes the key, the message block the plaintext.
The formula is Hi = Eg(Hi−1)(mi) ⊕ mi, with g massaging the chaining value into key format. Stephen Matyas, Carl Meyer and Jonathan Oseas of IBM published it in 1985, and it is essentially Davies–Meyer with the roles swapped. The feed-forward XOR of the message is what makes it hard to invert — without it you would just have encryption.
Because the key changes with the chaining value rather than the message, an attacker does not get to drive the key schedule directly. The construction survives in ISO/IEC 10118-2 and in Zigbee, whose AES-MMO hash exists so that tiny devices need not carry a separate SHA implementation.