Seven Obscure Languages in Seven Weeks: 'Writing Comments & "Hello World!" p. 3 & 4 (in PDF)

The book shows an interactive session like this:

1↩ ok 1
2↩ ok 2
"Hello"↩ ok 4
'W'↩ ok 5
BYE↩

However, when I try this (on both macOS & Linux (Mint), I get the following:

~$ gforth
Gforth 0.7.3, Copyright (C) 1995-2008 Free Software Foundation, Inc.
Gforth comes with ABSOLUTELY NO WARRANTY; for details type `license'
Type `bye' to exit
1  ok
2  ok
"Hello" 
:3: Undefined word
>>>"Hello"<<<
Backtrace:
$7FE7BE18FA68 throw 
$7FE7BE1A5DF0 no.extensions 
$7FE7BE18FD28 interpreter-notfound1 
'W'  ok
bye 
~$ gforth -v
gforth 0.7.3

The stack depth isn’t displayed anymore, and entering a String (with more than one character) causes an error and a stack trace.

Is this a mistake in the book? A bug in the Forth implementation? A misunderstanding on my side?

There are several current gforth implementations. The most recent one, 0.7.9 used in the book, allows string literals in quotation marks. The more “classical” one, 0.7.3, the one that you use, defines strings with a Forth word s": s" Hello". I am sorry about this confusion. I will add a note to the next edition.

0.7.3 is the latest actual release, according to gforth.org. But if you build the current git source also available from gforth.org, or run the forthy42/gforth Docker image, you get a build that reports its version 0.7.9, though it hasn’t been officially released yet.