< language > (BLISS, or allegedly, "System Software Implementation Language, Backwards") A language designed by W.A. Wulf at CMU around 1969.
BLISS is an expression language . It is block-structured , and typeless, with exception handling facilities, coroutines , a macro system, and a highly optimising compiler . It was one of the first non- assembly languages for operating system implementation. It gained fame for its lack of a goto and also lacks implicit dereferencing : all symbols stand for addresses, not values.
Another characteristic (and possible explanation for the backward acronym) was that BLISS fairly uniformly used backward keywords for closing blocks, a famous example being ELUDOM to close a MODULE. An exception was BEGIN...END though you could use (...) instead.
DEC introduced the NOVALUE keyword in their dialects to allow statements to not return a value.
Versions: CMU BLISS-10 for the PDP-10; CMU BLISS-11 , BLISS-16 , DEC BLISS-16C , DEC BLISS-32 , BLISS-36 for VAX / VMS , BLISS-36C .
["BLISS: A Language for Systems Programming", CACM 14(12):780-790, Dec 1971].
[Did the B stand for "Better"?]