Dear Haskell Café, I am pleased to announce opc-xml-da-client [1,2], an implementation of (the client side of) the OPC XML-DA data access protocol. While the OPC XML-DA protocol is quite dated (2003) and has largely been superseded by other OPC flavours, it is still being used in industrial environments. OPC XML-DA is based on SOAP and the data types in the Haskell package closely reflect the protocol specification as a web services description language document [5]. This package was developed by Mlabs [3] as contract work for my employer. We release it as FOSS, with Mlabs kindly hosting the project under their Github account. To my knowledge, besides PyOPC [4] this is the only freely available OPC XML-DA library and the only Haskell OPC library. We stopped using PyOPC because Python hit performance limits while parsing the XML. Feel free to contact me or Nikita Volkov at Mlabs if you have further questions. Cheers Olaf [1] https://github.com/mlabs-haskell/opc-xml-da-client [2] https://hackage.haskell.org/package/opc-xml-da-client [3] https://mlabs.city [4] https://pypi.org/project/PyOPC/ [5] https://opcfoundation.org/XMLDA/1.0/OpcXmlDa1.00.wsdl