The Corpus Cyrillo-Methodianum Helsingiense (CCMH) is a corpus of Old Church Slavonic (OCS) texts. It was collected at the University of Helsinki from 1986 to 2017, mainly as a side product of different research projects, and it remains a launching site rather than a completed project. The encoding and annotation of the texts is mostly very simple, and not all texts have been properly checked, but various scholars have used them as the basis of more sophisticated versions.
The work on CCMH was led by Prof. Jouko Lindstedt. After his retirement, the contact person for the corpus is now Max Wahlström. Lots of people have entered and checked the texts over the years, but especially Jussi Halla-aho, Edyta Jurkiewicz-Rohrbacher and the late Juhani Sarsila (1940–2006) have contributed to the work.