PuzzLex

Crossword Solver.
PuzzLex will help you to solve a wide range of word-based puzzles, such as crosswords, incomplete words, anagrams, multiple-word anagrams, and Countdown. Use the integrated Crossword Grid or simply type in the known letters of a word representing any unknown letters with a question mark. The program will search its comprehensive lexicons of words and phrases to show a listing of all possible matching words. The lexicon offers over 280,000 words. (Evaluation version only allows access to words up to 8 letters in length)
You can add and delete words, create your own lexicons, or import one from other sources. Registration provides the ability to search for words up to 30 characters in length.
PuzzLex also contains over 100,000 definitions, synonyms and antonyms.
If you're a word-puzzle enthusiast, PuzzLex is an essential tool.