ICE (Michael Lamanuzzi)
From Just Solve the File Format Problem
ICE is an obscure file compression utility, and associated compressed file format, developed by Michael Lamanuzzi. It runs on DOS.
For other formats named ICE, see the ICE disambiguation page.
Format details
Compressed files start with a 4-byte integer representing the original file size. There is no signature.
ICE format seems to be identical to Yoshizaki's LZHUF (modulo LZHUF's non-portable header).