I have been disassembling a large software project on my own, as a hobby. It is an educational exercise and I have learned a lot in the process. That said, I feel that my progress would be considerably quicker if I was to collaborate on the project with other like-minded individuals.
Herein lies the problem -- maybe. I am reversing this software for personal interest and potentially (but unlikely; given the magnitude of the codebase in question) implementing an interoperable service to interact with this software, replacing the vendor's own service. My (very limited) understanding is that this particular use-case is protected under copyright law.
However, my wish is to collaborate with others freely on the Internet, in a similar system employed by open source projects: version control repositories of assembly files, wikis to coordinate and share knowledge, public mailing lists, et cetera. I have a feeling this may be iffy at best.
Is what I want to do blatantly illegal, a gray area or even legally defensible? Would the situation be any different if the collaboration was in private rather than public? If it has any bearing on the answer, I am located in Australia and the software vendor in located in the USA.