Good dictionary software

What is good dictionary software? I am asking about the ones that can be downloaded and used on Windows machines, and not online websites.

I thought Word Web is a good one, but are there any advanced and good dictionaries?

I use the Merriam Webster CD version. In addition to being a fine dictionary, it has a lot of tools for searching that help you find entries whose meanings contain certain words, it does anagrams, and so on. I like words, and this one feeds my addiction.

I've tried many software dictionaries. Microsoft Encarta, Webster, Babylon, but the best one among them is Longman Dictionary of Contemporary English.

It has a lot of different features which helps you to learn English, pronunciation in two languages, a lot of examples for words, phrasal verb search, a thesaurus which helps you to understand the differences among similar words, pronunciation of the examples, word Activator and so on. It defines words and expressions in a very clear literature. It has vocabulary trainer, resource for teachers, pop up dictionary, and writing assistant.

Of course it has two problems. First, it doesn't have a good synonym and antonym bank as Microsoft Encarta has. Second, it's not pronouncing words any position of the page.

But overall, I think it's the best dictionary available for English language learners.