DiffDog

DiffDog is a differencing and merging tool developed by Altova, the Austrian software company known for its XMLSpy XML editor and MissionKit suite of developer tools. The product allows developers, technical writers and IT professionals to compare and merge text files, source code, directories, XML documents and database content. It addresses the need to identify changes accurately in files and data structures that may be large, complex or stored in different formats, where manual comparison would be slow and error-prone. DiffDog's approach extends conventional text comparison with structure-aware features, particularly for XML and databases, so that differences can be interpreted in the context of elements, attributes, schemas and records rather than just lines of text. This makes it valuable in environments where structured data and configuration files play a central role.

Key features include side-by-side comparison of text and source code files with syntax colouring, line and character-level highlighting, and editing directly within the comparison view. Directory comparison identifies added, removed and changed files across folder trees, including within ZIP archives, and supports synchronisation. XML-aware comparison can ignore whitespace, namespaces, attribute order and other non-significant differences, and XML Schema comparison allows elements to be mapped between schemas to generate transformation stylesheets. Database comparison covers both schema and data across major relational databases, such as SQL Server, Oracle, MySQL, PostgreSQL and IBM Db2, and can produce scripts to synchronise differences. Word document comparison and three-way merging for resolving conflicts are also supported. DiffDog integrates with version control systems and can be run from the command line for automation, and it works alongside other Altova tools in the MissionKit bundle. It runs on Windows and is offered in Professional and Enterprise editions. The tool is aimed at software developers, database administrators, XML and data integration specialists and quality assurance teams. Pricing starts from around USD 139 with a free trial, and a free version is also available.