Why not have Lego like Software?
Doug McIlroy, the inventor of UNIX pipes is quoted as &quot;Write programs that do one thing and do it well. Write programs to work together. Write programs to handle text streams, because that is a universal interface.&quot;.<p>I know it&#x27;s probably not exactly what you&#x27;re looking for but &quot;Do one thing and do it well&quot; tools and UNIX pipes to connect such single-purpose tools in my opinion is quite close to a &quot;pluggable building blocks&quot; metaphor.<p>In terms of web applications the REST paradigm and data represented as JSON structures is a similar smallest common denominator.<p>Someone else has already mentioned Christopher Alexander&#x27;s pattern language approach. Design patterns and Atomic Design are similar concepts for the software development domain.