1) It extracts words with frequency between 7,000 and 20,000 from
any Web page, the typical vocabulary gap between ESL learners and
native English speakers.
2) You can look up the words extracted with just a click (the browser requirements: IE 5.5 and above required).
3) Dictionary shows up in a popup window. It will not work if popup window is blocked in your browser (the browser requirements: IE 5.5 and above required).