I have recently come across this article (and those linked by it), while I was considering a rewrite for my own pet project.
While I tend to think that rewriting from scratch is usually a bad idea, if we are talking about open source projects, there’s another element you should take into account: how pleasurable it is to work on it. If you end up with a big and hairy code base you cannot touch without suddenly feeling all sad and pessimistic about the fate of the world, you should realize that something has gone deeply wrong: you are supposed to work on your project for fun (yeah, to scratch an itch, maybe, too…), and when the fun stops, most of the reasons to continue disappear. You have no (paying) customers, you have no deadlines, you will be able (or unable, depending on what you do in the rest of your time) to pay your bills anyway.
At this point, either you throw everything into the garbage bin – which may be sad, disappointing and frustrating, both for you and your users – or you take whatever lessons you may have learned in the process, and use your extra wisdom to start from scratch a hopefully better and more mature design and implementation that won’t have those shortcomings that brought you to this miserable situation.
It will probably have other defects and issues, though, more subtle and harder to spot in an upfront design. You have to accept it. And you have to accept the fact that you may need to start from scratch once again in the future.
Here is a simple form you can use to announce your decision to start from scratch. Just copy-paste it into your blog, filling in the required fields. It may save you precious time that you will be able to spend on your n-th rewrite :)
I'll rewrite my pet project from scratch because: [ ] It's not modular enough [ ] The original design didn't take __________________ into consideration [ ] It's too slow [ ] There is too much legacy code which I can't seem to get rid of [ ] I want to write it in ____________________ ---- [ ] And this time I'll use TDD/BDD [ ] And this time it will be done right! Signed (the developer) _____________________________