I have had my online vocabulary extraction tool available on the web for a while now. I have gotten a lot of use out of it myself, as my primary interest has been to develop more vocabulary to increase reading ability. The application generally works ok, but it suffers from some technical issues. Because it loads the entire CC-CEDICT every time it runs, it taxes the shared hosting provider a lot, to the point where the script crashes unpredictably, especially for larger texts. It also requires manual intervention to keep the dictionary up to date, and adding more dictionaries takes a lot of additional effort.
Meanwhile, for the past year I’ve been working on a similar program that can be used offline. It has been working well, is a little faster, and is easier to drop in newer versions of the CC-CEDICT dictionary. I have spent a few months adding a little more polish to it, and now am releasing it as open source software. At this point, it is available for Windows systems. The source code is also available, which would allow it to be used on nearly any system. More details are at the project page and the documentation page. Here are some screenshots to demonstrate its functionality: