How can I find out which Informix products/versions are compliant/compatible with other Informix product/version combinations?
Try calling your local Informix office. They may have something. As a general rule, most Informix products can work well with other versions. If you can't find the info you need, try posting a query on the USENET newsgroup: comp.databases.informix. Give a specific question, such as "Has anybody gotten Version XXX of product YYY to work with Version AAA of Product BBB on the ZZZ operating system?"