This document discusses open educational resources (OER) projects at Tallinn University. It defines OERs as resources with open access, open licensing, open formats and open source features. It then describes several OER authoring tools and repositories developed at or used by Tallinn University, including LeMill (a collaborative authoring community), TATS (a question and test authoring system), and Krihvel (a learning resource authoring tool). It provides details on LeMill, including its design and use by teachers for finding, authoring and sharing open learning resources. Usage and membership statistics for LeMill are presented. Finally, it briefly mentions some other OER software developed at Tallinn University.