Michael Schwern has a great bunch of slides up at http://www.pobox.com/~schwern/talks/Refactoring/. They cover refactoring, object oriented perl, design patterns, and some other stuff that should be of interest to those who write/refactor either Perl or other languages.
I've been working on rewriting several thousands lines of VBA code in clean, readable, maintainable perl. The idea is to parse an export file from a drafting program, then store the information in an Databases for easy reporting using Crystal. The VBA code is not very nice: no use of data structures, no comments, no code formatting (indenting), low code reuse (much copy & paste), many temporary files, bad variable names (varA, varB, lenVarB, etc), and bad function names (Four, sb, etc). Should be a good case study for refactoring as well.
There's a good tutorial on refactoring for .NET/C# - http://www.parlezuml.com/tutorials/dotnet_refactoring/intro.htm
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