After far too long, and far too many obstacles to be overcome, Dave MacQueen, Lars Bergstrom, and I have finally prepared an open-source site for the entire family of languages derived from Standard ML. The defining characteristic of Standard ML has always been that it has a rigorous definition, so that it is always clear what is a valid program and how it should behave. And indeed we have seven different working compilers, all of which are compatible with each other, with the exception of some corner cases arising from known mistakes in the definition. Moreover, there are several active projects developing new variations on the language, and it would be good to maintain the principle that such extensions be precisely defined.
To this end the sources of the 1990 and 1997 versions of the definition are on the web site, with the permission of MIT Press, as is the type-theoretic definition formulated by Stone and H., which was subsequently used as the basis for a complete machine-checked proof of type safety for the entire language done by Crary, Lee, and H. It is be hoped that the errors in the definition (many are known, we provide links to the extensive lists provided by Kahrs and Rossberg in separate investigations) may now be corrected. Anyone is free to propose an alteration to be merged into the main branch, which is called “SML, The Living Language” and also known as “Successor ML”. One may think of this as a kind of “third edition” of the definition, but one that is in continual revision by the community. Computer languages, like natural languages, belong to us all collectively, and we all contribute to their evolution.
Everyone is encouraged to create forks for experimental designs or new languages that enrich, extend, or significantly alter the semantics of the language. The main branch will be for generally accepted corrections, modifications, and extensions, but it is to be expected that completely separate lines of development will also emerge.
The web site, sml-family.org is up and running, and will be announced in various likely places very soon.
Update: We have heard that some people get a “parked page” error from GoDaddy when accessing sml-family.org. It appears to be a DNS propagation problem.
Update: The DNS problems have been resolved, and I believe that the web site is stably available now as linked above.
Update: Word smithing for clarity.