Matchmaker, MACH Interface Generator (MIG) - Automated generation of multilingual interprocess communication interfaces. Abstract and PS/DOC files. - http://www.cs.cmu.edu/afs/cs/project/mach/public/www/doc/abstracts/mig.html
Inter-Language Unification (ILU) - a multi-language object-oriented interface definition system developed at Xerox Parc. - ftp://ftp.parc.com/pub/ilu/ilu.html