# get the versions in context
locate .pm | grep 'pm$' | xargs | xargs grep -C2 '$VERSION.*=' > versions-C2

# find the interesting versions
perl -nle 'if(/\.pm:(.*)/){s/\d/1/g;print}' versions-C2 | sort -u | less

# find the popular versions (w/ roughly canonical lines)
perl -nle 'if(/\$VERSION.*=/) { s/.*\.pm://; s/\s+/ /g; s/\d+/1/g; print }' \
  versions-C2 | sort | uniq -c | sort -rn | head -n 10 | nl