Regina

Documentation (AROS regarding REGINA) you find here. Obviously based on version 3.0.

Instructions

ADDRESS ARG BREAK CALL DO/END DROP EXIT IF/THEN/ELSE INTERPRET ITERATE LEAVE NOP NUMERIC OPTIONS PARSE PROCEDURE PULL PUSH QUEUE RETURN SAY SELECT/WHEN/OTHERWISE SIGNAL TRACE UPPER

Build in functions:

ABBREV ABS ADDLIB ADDRESS ALLOCATED ARG B2C B2X BEEP BITAND BITCHG BITCLR BITCOMP BITOR BITSET BITTST BITXOR BUFTYPE C2B C2D C2X CD CENTER CENTRE CHANGESTR CHARIN CHAROUT CHARS CHDIR CLOSE COMPARE COMPRESS CONDITION COPIES COUNTSTR CRYPT D2C D2X DATATYPE DATE DELSTR DELWORD DESBUF DIGITS DIRECTORY DROPBUF DUMPFILES DUMPTREE DUMPVARS EOF ERRORTEXT EXISTS EXPORT FREELISTS FREESPACE FUZZ GETCLIP GETENV GETPATH GETPID GETSPACE GETTID HASH IMPORT INDEX INSERT JUSTIFY LASTPOS LEFT LENGTH LINEIN LINEOUT LINES LISTLEAKED MAKEBUF MAX MEMORYSTATS MIN OPEN OVERLAY POPEN POS PRAGMA QUALIFY QUEUED RANDOM RANDU READCH READLN REMLIB REVERSE RIGHT RXFUNCADD RXFUNCDROP RXFUNCERRMSG RXFUNCQUERY RXQUEUE SEEK SETCLIP SHOW SIGN SLEEP SOURCELINE SPACE STATE STREAM STRIP STORAGE SUBSTR SUBWORD SYMBOL TIME TRACE TRIM TRACEBACK TRANSLATE TRUNC UNAME UNIXERROR UPPER USERID VALUE VERIFY WORD WORDINDEX WORDLENGTH WORDPOS WORDS WRITECH WRITELN X2B X2C X2D XRANGE

more informations are here

Documentation of AREXX commands is here.

If you compare instructions ECHO and SHELL are not in regina. All other commands are in AREXX and REGINA.

Documentation of AREXX functions is here.

if I compare the functions regina has much more functions because it is based on a more uptodate version of REXX. It also includes rexxsuuport.library and rexxsyslib.library. I have tested "addlib" to open rexxsupport.library and it worked.