Python has supported using dynload_shlib (using dlopen) on AIX since https://github.com/python/cpython/commit/c19c5a62aef7dce0e8147655b0d2f087965fae75 in 2003. While I have not found a definitive timeline of when AIX gained support for dlopen, I have found references going back to at least 2000. Considering this is now 20 years later and all supported AIX versions support dlopen, I suspect nobody has used or tested this code path in quite some time. I propose removing this support under PEP 11.

If Python has been defaulting to dlopen() on AIX systems that support it, there is no reason to maintain the historical, AIX-specific load() support in dynload_aix.c

I believe that dlopen() was introduced on AIX in release 4.3.  The official end of support for AIX 4.3 was 2003, so I doubt there are any customers on extended support, or at least those customers are unlikely to install Python 3.11.

I've opened a PR to disable support in 3.10 with removal in 3.11 according to the guidelines outline in PEP 11. Given the unlikeliness that anyone is actually still using this feature (and are possibly already broken by a bunch of other things), would it make more sense to do the removal in one go? I do see that systems without multithreading support were both unsupported and removed in 3.7, though I do not know the particulars of why that is the case since most other entries have a 1 version gap.

I think we should just axe it.

Ok, I have updated the PR to remove it completely.

New changeset 1dd6d956a3ddf2cf6d4a69241dba8cd1379421b9 by Kevin Adler in branch 'master':
closes bpo-42030: Remove legacy AIX dynload support (GH-22717)
https://github.com/python/cpython/commit/1dd6d956a3ddf2cf6d4a69241dba8cd1379421b9