I downloaded clisp from https://sourceforge.net/projects/clisp/ and cloned FRL from github repo https://github.com/lispm/FRL/tree/master
I tried following the following instructions https://github.com/lispm/FRL/blob/master/setup.text but on step 3 I got next error:
Break 5 [8]> (load "labs/FRL/init.lisp")
;; Loading file labs\FRL\init.lisp ...
*** - READ: input stream #<INPUT BUFFERED FILE-STREAM CHARACTER #P"labs\\FRL\\init.lisp" @72> ends within a token
after multiple escape character
The following restarts are available:
ABORT :R1 Abort debug loop
ABORT :R2 Abort debug loop
ABORT :R3 Abort debug loop
ABORT :R4 Abort debug loop
SKIP :R5 skip (PACKAGE-DECLARE FRL GLOBAL ...)
RETRY :R6 retry (PACKAGE-DECLARE FRL GLOBAL ...)
STOP :R7 stop loading file D:\University\Subjects\knowledge engineering\CLISP\clisp-2.49\labs\FRL\frlpkg.lisp
ABORT :R8 Abort debug loop
SKIP :R9 skip (PACKAGE-DECLARE FRL GLOBAL ...)
RETRY :R10 retry (PACKAGE-DECLARE FRL GLOBAL ...)
STOP :R11 stop loading file D:\University\Subjects\knowledge engineering\CLISP\clisp-2.49\labs\FRL\frlpkg.lisp
ABORT :R12 Abort main loop
Briefly, you can't: FRL was written for MACLISP and Franz Lisp, both of which are obsolete Lisp dialects which predated CL. The instructions in setup.text are describing how to get it to work on Franz Lisp (so probably on a Vax). This is historical code.
You might be able to make a lot of changes to it to make it work, but it's not going to work out of the box. You also might be able to coerce some version of either MACLISP or Franz Lisp to run: MACLISP would need a PDP-10 emulator, there was a port of Franz Lisp to x86 but it was 30 years ago now: I have no idea if it would still work / be possible to make it work.