Progress Linux has two logos: one logo is for official use; the other logo to indicate endorsement by the project; the other for unofficial use that does not indicate endorsement by the project.
For both logos the following license applies:
Copyright (C) 2010 Progress Linux This work is free: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This work is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. The complete text of the GNU General Public License can be found in /usr/share/common-licenses/GPL-3 file.

More artwork and logo variations (i.e. orientation, color, etc.) are available in the artwork and logos Git repositories, e.g.: