It should be noted that this paper was released before the Ada 95, Ada 2005, Ada 2012, and soon-to-be Ada 2022 standards were published:<p>Ada 95: <a href="https://www.adahome.com/rm95/" rel="nofollow noreferrer">https://www.adahome.com/rm95/</a><p>Ada 2005: <a href="https://www.adaic.org/resources/add_content/standards/05rm/html/RM-TTL.html" rel="nofollow noreferrer">https://www.adaic.org/resources/add_content/standards/05rm/h...</a><p>Ada 2012: <a href="http://www.ada-auth.org/standards/12rm/html/RM-TTL.html" rel="nofollow noreferrer">http://www.ada-auth.org/standards/12rm/html/RM-TTL.html</a><p>Ada 2022 (draft): <a href="http://www.ada-auth.org/standards/ada22.html" rel="nofollow noreferrer">http://www.ada-auth.org/standards/ada22.html</a><p>The paper's abstract states: "Although Ada supports concurrency and can thus be used as a concurrent programming language, it is not generally considered to be an object-oriented programming language."<p>Object-oriented programming was added in Ada 95, so this paper is probably not relevant to modern programming unless you are interested in the history of the Ada programming language.