[gnaffle]

I think the big danger Spolsky warns about is the "stop working on the old code and spend a year doing a complete rewrite". Many very smart people have underestimated the risks in doing that and the time it will take, while overestimating the benefits.

A smarter approach is to rewrite parts of the code. Apple has done that with many apps (and even iOS is OSX with a new UI/API on top). Linux has had many patch-by-patch rewrites as well. With a webapp, a "complete rewrite" still might leave most of the heavy lifting to the web framework, and you might be able to keep most of your HTML, CSS and JS.

I think the well-executed rewrites usually include launching an entirely new product while still supporting the old one. Adobe did this with InDesign (replacing PageMaker), Apple did this with OSX (the initial releases included OS9) and Microsoft did it with NT while keeping Windows 9X around.

[yuhong]

Yea, the WaSP was in 1998 petitioning Netscape to cancel Mariner, and unfortunately they caved.