.article {
  column-count: 2;
  column-gap: 20px;
}

http://www.alistapart.com/articles/css3multicolumn

The W3C multi-column module is a CSS level-three working draft, proposed by the W3C to extend the current CSS box model. The module’s intent is to allow content to flow into multiple columns inside an element. It offers new CSS properties that let the designers specify in how many columns an element should be rendered. The browser takes care of formatting the text so that the columns are balanced.

The proposed new CSS properties are:

    * ‘column-count’, to determine the number of columns into which the content of the element will flow.
    * ‘column-width’, to describe the optimal width of each column.
    * ‘column-gap’, to set the padding between columns.
    * ‘column-rule’, to define a border between columns.

CSS3 Multicolumn text

CSS3

CSS