Concise Command Language (CCL) was the term used by Digital Equipment Corporation for the command-line interpreter / user interface supplied on several of their computing systems; its successor was named DIGITAL Command Language (DCL).

CCL provides the user with an extensive set of terminal commands.^[1]

The first operating system to include CCL was DEC's TOPS-10.^[2]

The PDP-6 monitor came with a simple set of commands. To compile and run a FORTRAN program, one would

1. .R F4  ———  invoke the FORTRAN compiler
2. user input  ———  specify binary output and source input
3. .R LOADER 30  ———  invoke the loader, allocate 30K of memory
4. *DTA1:PROG3  ———  specify binary object to load
5. *SYS:/S  ———  let the loader find the appropriate subroutine libraries
6. .SAVE DTA1:PROG3  ———  write the executable to DTA1

(The .(DOT) is a monitor prompt and the *(Star/Asterisk) is an application prompt)

The PDP-10 monitor (later called TOPS-10) had CCL. Key to its improvements over its predecessor were:^[2]

• multi-step commands: .EX PROG3,SUB3A,SUB3B
  • would check to see if any of the 3 needed to be recompiled (and did so if necessary)
  • run the object program loader (including needed subroutine libraries)
  • start running the program
• advanced command file: .EX @RUNPROG3.CMD
  • would run the command(s) in the .CMD file

The following table contains a list of CCL commands.^[1]