> What limitations do mailing lists impose on open source development that are not present in other tools?
None, in my opinion. On the contrary, they are the only tool that demand a structure — just by the nature of e-mail messages — that is coherent enough to be highly useful when searching archives later.
> On the contrary, they are the only tool that demand a structure — just by the nature of e-mail messages
Newsgroups also have this structure and they have the advantage of easily doing an archive search (by being able to download part of or the entire message archive of a given group and using the search features of your mail/news client).
None, in my opinion. On the contrary, they are the only tool that demand a structure — just by the nature of e-mail messages — that is coherent enough to be highly useful when searching archives later.