The Perseus Project has some of the neatest data around and I just love their vocabulary lists that can be generated.
I can probably help you out as I have played around with their xml feed in the past. I experimented with building an interface to select and build specific vocabulary lists, the problem I found was the server seemed unresponsive quite often. So much so that it would not provide a stable experience for users. I abandoned my approach after I saw that they offer a full data download.
Was there a specific vocabulary list you were looking for? I wrote this simply php script which can fetch a word and it can be modified to grab an entire list. Once grabbed it can be saved to a .csv file. Easy peasy lemon squeezy.
Here's a sample file that request a word from Perseus.http://www.textkit.com/xml.php