While this is clearly just an MIT variant, the PostgreSQL community felt strongly enough about this license that they submitted a template form of the variant that they use for OSI approval and it was granted in February 2010.
Please note that only licenses which use this _EXACT_ text, with <YEAR> and <ORGANIZATION> substituted in can be considered to be under the PostgreSQL license. Similar licenses are almost certainly MIT and NOT PostgreSQL.
Copyright (c) <YEAR>, <ORGANISATION> Permission to use, copy, modify, and distribute this software and its documentation for any purpose, without fee, and without a written agreement is hereby granted, provided that the above copyright notice and this paragraph and the following two paragraphs appear in all copies. IN NO EVENT SHALL <ORGANISATION> BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF <ORGANISATION> HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. <ORGANISATION> SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND <ORGANISATION> HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.