Comment by sundarurfriend

The Julia General registry is locally stored as a tar.gz and has version info for all registered packages, so I tried this out for Julia packages. The top 5 are:

    DiffEqBase                  6.189.1   
    LoopVectorization           0.12.172  
    Reactant                    0.2.161   
    Mooncake                    0.4.159   
    Distributions               0.25.120  

So, no crazy numbers or random unknown packages, all are major packages that have just had a lot of work and history to them. Out of the top 10, pretty much half were from the SciML ecosystem.

Caveats/constraints: Like the post, this ignores non-SemVer packages (which mostly used date-based versions) and also jll (binary wrapper) packages which just use their underlying C libraries' versions. Among jlls, the largest that isn't a date afaict is NEO_jll with 25.31.34666+0 as its version.