There are a large number of OER rubrics in use at many different universities, however they tend to be variant upon one of three basic OER Rubrics listed below.
The Affordable Learning Georgia rubric is the simplest and most straight-forward, and combines both textbook evaluation and ancillary material evaluation. No license information is given for this rubric.
BCCampus has three rubric checklists: One for faculty, one for administrators, and one for students. While there is significant overlap in the three rubrics, they can help the evaluator look at the OER from different perspectives. These rubrics are licensed under a CC-BY 4.0 license.
This rubric has the greatest granular breakdown, and is a useful tool if you need extensive documentation about how each level of criteria is evaluated. This document is licensed under a CC-BY 3.0 Unported License.