Depending on how thorough you want to be, if you're including the $ at the end, you might as well include the ^ at the beginning.

Also, maybe someone can answer this for me. Is there an advantage to matching the \. as part of the second atom? That is to say, what is the advantage of

$name =~ /^(.+)(\..+)$/ or die "$name is an invalid patch name";
"$1$platform$2";
[download]

over

$name =~ /^(.+)\.(.+)$/ or die "$name is an invalid patch name";
"$1$platform.$2";
[download]

As an aside, I noticed you're looking for files ending in both .Z and .tar. Is it possible you will want to match files ending in .tar.Z (or .tar.gz) as well?