To start FMSLogo, just click on the FMSLogo icon. To exit FMSLogo, enter the command BYE or File-Exit.

If you invoke a procedure that has not been defined, FMSLogo first looks for a file in the current directory named proc.lgo where "proc" is the procedure name in lower case letters. If such a file exists, FMSLogo loads that file. If the missing procedure is still undefined, or if there is no such file, FMSLogo then looks in the library directory for a file named proc (without the ".lgo" extension) and, if it exists, loads it. If neither file contains a definition for the procedure, then FMSLogo signals an error.

Many of FMSLogo's built-in procedures are included in the default library, so if you use a different library you may want to include some or all of the default library in it.