Desktop Connection Library
A multi-platform communication framework created by Paul Guyot, Nicolas Zinovieff, and Michael Vacík. DCL was designed to replace the various code libraries and applications developed by Apple for connecting to and interacting with data stored on devices running Newton OS 2.0 and later via the built-in dock protocol. Connections are usually performed via serial cable, but higher level protocol layers can also run over other connection methods such as TCP/IP.
Internet Archive: Desktop Connection Library