>> What about this? From
>> <http://se.ethz.ch/~meyer/ongoing/etl/LANGUAGE-TABLE.pdf>:
>>
> Can't tell for sure because the pdf doesn't contain anything beyond the
> table of contents, but this seems to be the right set of concepts.
>
> And from the number of pages, it may be more extensive than what I
> remember.  Maybe I had an earlier edition.  Or maybe I misremember the
> size.

LACE stands for Language for Assembly Classes in Eiffel. The files in
which it is written are called "Ace files". More links:

http://se.inf.ethz.ch/courses/2013b_fall/eprog/additional_materials/eiffel_the_essentials.pdf

https://archive.eiffel.com/doc/online/eiffel50/intro/studio/index-05.html

https://wiki.liberty-eiffel.org/index.php/ACE

https://dev.eiffel.com/ACE_to_ECF:_The_Transition_Explained
("ACE to ECF: The Transition Explained. This page addresses the
rationale behind EiffelStudio's new ECF configuration format, and
clarifies which needs were covered by the new system. ECF stands for
Eiffel Configuration File.")