Open Source software is software, where the source code is shared with everyone. This means that many people can contribute to the code, that improvements are rapidly integrated and that the planning is extensively user-based.
DataCleaner is licensed under the terms of the Lesser General Public License (LGPL) which allows anyone to use the software for all purposes, but any modifications made to the code must be contributed back to the community.

Master Data Management (MDM) can loosely be translated into "management of reference data". This means all the data that is non-transactional and can be shared globally within a company or organization. Examples are datasets containing customers, employees, products, office-locations etc. To perform data quality analysis on these data is a crucial task to ensure usefulness and correct use throughout the organization.

Extract-Transform-Load (ETL) is the process of copying and transforming data from one or more datasources to another. Typically you would use a tool like DataCleaner before, during and after any ETL activity.

• Before, to gain insight into the datasources that you are about use in your work. We typically refer to this as looking below the tip of the iceberg of data.
• During, if (when) you run into any unexpected mismatches during the ETL process.
• After to ensure consistency and quality in the datasource that you have populated.