One appeal of a rewrite is that you can do it properly. I think this is based on the misconception that just because you created something, you understand it.

One appeal of a rewrite is that you can do it properly. I think this is based on the misconception that just because you created something, you understand it. In fact, we build software (or grow it). Where we end up is more like where an explorer ends up in an unknown region. Very few people prove even one aspect of a small part of their programs, and it takes them a long time. We understand our code no more than we understand our bodies. There's no need to make an effort to rewrite, because with the next disruptive platform, the same old stuff all gets rewritten/reinvented anyway (current egs: JavaScript (web); objective-c (iPhone)). BTW: Joel's famous article on mozilla: http://www.joelonsoftware.com/articles/fog0000000069.html http://www.joelonsoftware.com/articles/fog0000000069.html