The program brought to your attention does so, that Wikipedia it appears in literal sense always near at hand . The program works in a resident mode but when you meet an unknown word in the text, you simply select it and press Ctrl twice.It leads to occurrence of the yellow tooltip which contains the text by the selected word from Wikipedia.
WikiReader makes loading and reading of WikiPedia articles easier. All you have to do is to press a hotkey in any Windows application, and the WikiPedia article will pop up in a small window. In the WikiReader window, articles from WikiPedia are displayed without menus, logos or other distracting elements. Already viewed articles are cached, thus reducing their loading time and enabling them for reading offline.