Eclipse EMF Diff/Merge 0.4.0 Release Review

End Date of the Review Period: 

Reviews run for a minimum of one week. The outcome of the review is decided on this date. This is the last day to make comments or ask questions about this review.

Wednesday, December 3, 2014



EMF Diff/Merge is a diff/merge tool for models. Its main purpose is to help build higher-level tools that need to merge models based on consistency rules. Typical usages include model refactoring, iterative model transformations, bridges between models or modeling tools, collaborative modeling environments, or versioning systems.

This release includes the core diff/merge technology and two sample applications: a GUI for interactive merging, and a tool dedicated to the creation, application and reuse of modeling patterns.

Architectural Issues: 

The EMF Diff/Merge technology is made of two update sites/dropins:

  • A core EMF Diff/Merge update site that provides:
    • A diff/merge engine. This component can be customized/extended via model scopes (what to compare), match and diff policies (how to compare) and merge policies (how to merge).
    • A GUI component which relies on the engine. This component provides an extension point which allows specifying engine customizations that are made available in the GUI. It comes with a simple customization for GMF scopes (diagrams and models) that illustrates the overall extendibility of the technology.
  • A "Pattern" update site which relies on the update site above. It contains two features:
    • A tool that provides support to modeling patterns that can be defined in terms of diff/merge.
    • An extension of this tool for Sirius environments.


Security Issues: 

No security issue identified.

Non-Code Aspects: 

The complete EMF Diff/Merge documentation is available from the EMF Diff/Merge Wiki page:

Among the applications mentioned, one refers to the wiki page dedicated to Modeling Patterns, which is structured similarly to the main page.

Usability Details: 

EMF Diff/Merge intends to conform to the User Interface Guidelines.

End of Life: 

No EMF Diff/Merge component is deprecated so far.


EMF Diff/Merge does not implement any standard.


EMF Diff/Merge obtained the "Most innovative project/feature" award at EclipseCon NA 2013. It is a young project whose usage is spreading.

The forum, bugzilla and Gerrit show regular activity by different people and organizations. In particular, several Gerrit pull requests have been submitted by people external to the project.

Questions on the forum arise on a regular basis, some of them receiving significant attention: the thread with the highest number of views has a total of almost 14,000 views.