Metaphone 3
A professional version was released in October 2009, developed by the same author, Lawrence Philips. It is a commercial product but is sold as source code. Metaphone 3 further improves phonetic encoding of words in the English language, non-English words familiar to Americans, and first names and family names commonly found in the United States. It improves encoding for proper names in particular to a considerable extent. The author claims that in general it improves accuracy for all words from the approximately 89% of Double Metaphone to over 99%. Developers can also now set switches in to code to cause the algorithm to encode Metaphone keys 1) taking non-initial vowels into account, as well as 2) encoding voiced and unvoiced consonants differently. This allows the result set to be more closely focused if the developer finds that the search results include too many words that don't resemble the search term closely enough. Metaphone 3 is sold as C++, Java and C# source.
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