This book constitutes the refereed proceedings of the 7th International Conference on Compiler Construction, CC "98, held as part of the European Joint Conference on the Theory and Practice of Software, ETAPS "98, in Lisbon, Portugal, in March/April 1998. The volume presents 19 revised full papers selected from a total of 50 submissions; also four system demonstrations and an abstract of an invited talk are included. The papers cover the classical issues of compiler construction centered around computer languages and their processors, with an emphasis on practical methods and tools, but also other aspects of language processing are addressed like interpretation, editing, and debugging.