An extensive revision of ALGOL 60 by Adriaan van Wijngaarden et al. ALGOL 68 was discussed from 1963 by Working Group 2.1 of IFIP. Its definition was accepted in December 1968. ALGOL 68 was complex, and posed difficulties for both implementors and users. It featured structural equivalence automatic type conversion ("coercion") including dereferencingflexible arrays generAlised loops (for-from-by-to-while-do-od), if-then-elif-fi, an integer case statement with an ' out' clause skip and goto statements blocksprocedures user-defined operators {procedure parameters} {concurrent} execution (cobegin/coend) semaphores generators "heap" and "loc" for {dynamic allocation}. It had no {abstract data types} or {separate compilation}. (1995-05-01)