Support SRU (Search/Retrieve by URL) in addition to Z39.50
Sierra supports Z39.50 but not SRU. Remote search and import/overlay of records from SRU-only sources seems to be increasingly important. We have begun to encounter potential partners who are no longer able to offer Z39.50 access because their systems only support SRU; likewise, we would like to be able to offer SRU ourselves to maximize interoperability.
GPL-licensed software is available to add SRU support to Z39.50-capable systems such as Sierra (for example, CQL-Java, yazproxy and metaproxy):
https://www.loc.gov/standards/sru/
https://www.indexdata.com/resources/software/cql-java/
https://www.indexdata.com/resources/software/yazproxy/
https://www.indexdata.com/resources/software/metaproxy/
