Selingua is a vocabulary training program with extensive built-in dictionaries -- more than 2000 words in each of the following languages: English (both American and British), German, Spanish, French and Swedish. It is a freeware free vocabulary training application.
Here is a screenshot to illustrate the features and user interface of this application:
BOINC
WhatPulse
LTspice
Zyzzyva
Typing Master