Run the CAS compiler by running the QCOMPILE.EXE file in your Quest directory or selecting "Quest Compiler" from the Quest section in your Start menu.
Using QCompile is simple - choose an input .ASL file by clicking the "Browse" button by "Input .ASL file", and then select an output file by clicking the "Browse" button by "Output .CAS file". Then click "Compile" and the .CAS file will be created in the location specified. The .CAS file can then be loaded into Quest and/or distributed as required, just like an ASL file - except that other people won't be able to see your game code, or edit it.
The CAS file contains all of your game code, and it can also contain any pictures, sounds or other files included by your game if you select the option. See !resource and extract for information on manually including and extracting files.
The CAS compiler can also be run from a command line, using the following syntax:
QCOMPILE [input file [; output file] ]
For example:
QCOMPILE mygame.asl
will load the compiler with "mygame.asl" entered in the "Input .ASL file" box;
QCOMPILE mygame.asl; mygame.cas
will load the compiler and compile "mygame.asl" to "mygame.cas", without displaying the compiler window. The progress bar and confirmation message are still displayed.