After a conversation on the Software Design mailing list, and a question in PerlMonks about how to find the minimum version of perl needed to run a script, I thought I'd stop pissing around and complete Perl::MinimumVersion.
It just went up to CPAN.
In short, you give Perl::MinimumVersion a Perl document (filename, raw source, PPI::Document object) and it tells you what version of perl you need in order to run it.
And being a good PPI-using citizen, it does this without having to run or load the code in question.
At the moment, the coverage of the various syntax things is a bit weak, but the good news is that each syntax check is expressed as a single 5 or 6 line function.
So for any specific features people know of, feel free to cut and paste to make a new check function, then just file it in rt.cpan.org with the version number, and I'll merge in whatever comes my way.
Or you are more than welcome to just get commit rights to the Parse::Perl SourceForge project, and you can add the check functions straight to the module in CVS.