[fsloth]

Joel has lots of right things to say, but I'm afraid that one - "Never rewrite from scratch" - is far too sternly interpreted to the point where it is actually more harmful than beneficial.

Of course you can rewrite from scratch. You just should not expect to reach the same feature coverage instantly, and should approach the work methodically. Most of all, you should have a good reason. "This code is spaghetti" is usually not one. "I want to implement feature X and the current codebase does not really support is" could be a good reason.

Also, a rewrite is pointless from the point of view of code quality unless you are familiar with similar codebases operating in a similar domain.

Main advantages or rewrite are, that when you are a domain expert and implementing and designing core routines, you get constant flashes of intuition "Aha, I should add this interface here because that will enable me to implement Foo and Bar using this instead of writing a FooSubsystem and BarSubsystem" and so on.

If you have no experience from the domain, you get those insights only after you've written the code and are actually new proud owner of new heap of semi-maintainable code.