Source : Free On-Line Dictionary of Computing

RTL/2
     
        Real Time Language.
     
        A small {real-time} language based on {ALGOL 68}, with
        {separate compilation} designed by J.G.P. Barnes of ICI in
        1972 as a successor to {RTL/1}.
     
        A program is composed of separately compilable modules called
        "bricks" which may be datablocks, procedures or stack.  A
        stack is a storage area for use as a workspace by a task.  The
        language is {block-structured} and {weakly typed}.  Simple
        types are byte, int, frac and real.  There are no {Boolean}s.
        Compound types may be formed from {array}s, {record}s and
        {ref}s (pointers).  There are no user-defined types.  Control
        statements are if-then-elseif-else-end, for-to-by-do-rep,
        block-endblock, switch, goto, and label variables.
     
        ["RTL/2: Design and Philosophy", J.G.P. Barnes, Hayden & Son,
        1976].