To compare two files in Eclipse, first select them in the Project Explorer / Package Explorer / Navigator with control-click. Now right-click on one of the files, and the following context menu will appear. Select Compare With / Each Other.
yy or Y to copy the line (mnemonic: yank)
or
dd to delete the line (Vim copies what you deleted into a clipboard-like "register", like a cut operation)
then
p to paste the copied or deleted text after the current line
or
P to paste the copied or deleted text before the current line
In the package explorer, in the upper right corner of the view, there is a little down arrow. Tool tip will say view menu. From that menu, select filters
From there, uncheck .* resources.
So Package Explorer -> View Menu -> Filters -> uncheck .* resources.
With Eclipse Kepler and OS X this is a bit different:
Best Answer
To compare two files in Eclipse, first select them in the Project Explorer / Package Explorer / Navigator with control-click. Now right-click on one of the files, and the following context menu will appear. Select Compare With / Each Other.