EDI 850 probably refers to ASC X12 EDI Transaction Set Identifier 850 (Purchase Order), published by DISA.

I don't believe there are any publicly available modules or even really publicly available documentation for ASC X12.

There's been a discussion on this subject over on Use Perl.

I've used Perl for manipulation of X12 documents, but I don't have anything releasable. The hard part isn't parsing the documents, it's getting the information about all the fields and coordinating with your partners on acceptable use of the standards (what they call Implementation Conventions or ICs).

If there were to be any Open Source development in X12, I think that I'd be able to help test and advise. I'd have to check with my employer if I could contribute otherwise.

I don't think this is relevant at all.

Well, this post (second message in the digest) surely makes the connection between EDI 850 and EDIfact.

Maybe it's just the new loose search engine on CPAN, but XML::EDI doesn't seem to find anything relevant.