Free to be re-used as long as attribution is given. The Copyright notice on the European Commission website states:
Reproduction is authorised, provided the source is acknowledged, save where otherwise stated.
Where prior permission must be obtained for the reproduction or use of textual and multimedia information (sound, images, software, etc.), such permission shall cancel the above-mentioned general permission and shall clearly indicate any restrictions on use.
There's also a specific legal notice from the Publications Office.