Scalar::Util is a good example of a module with an XS and PurePerl implementation.
My criteria for good software:
  1. Does it work?
  2. Can someone else come in, make a change, and be reasonably certain no bugs were introduced?

In reply to Re: How to implement CPAN module variants by dragonchild
in thread How to implement CPAN module variants by Jeffrey Kegler

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