The structured assembly language for the General Electric Company 4xxx range of computers and their OS4000 operating system . It is strictly an assembler in that the generated code is relatively predictable but it can be written in a sufficiently structured manner, with indentation, control statements, function and procedure calls, to make the resultant source easy to read and manage. Even with this visible structure however, it is important to remember that the assembly of the statement is done left to right.
The British videotext system, Prestel is programmed in Babbage.
[1980's article in Datamation].