The Open Source Initiative has created a trademarked logo that organizations can now use to signify that their products are covered under one of the licences approved by OSI (GPL, MPL, Apache, BSD, others).

The logo resembles a thick forest green annulus with a pie wedge cut out of the bottom to resemble a keyhole. Underneath the forest green keyhole logo is the text "OSI certifiedtm".

When companies distribute code or documentation on media that they want to publicize as covered by OSI, they must place the logo or the open source certification blurb prominently on it.

You can learn more about the trademark program at http://opensource.org/trademarks/