One of the most interesting videos on programming I've watched in a while addresses that idea: https://vimeo.com/108441214 The video can be summed in a lot of ways as "What if we actually took that seriously and started designing around it?"
I haven't had enough chance to do it, but I'm at least intrigued.
Isn't that the Unix philosophy in a nutshell? Lots of small programs that only do one thing, but can be strung together? They can also be rewritten without worrying about affecting anything else.
I haven't had enough chance to do it, but I'm at least intrigued.