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The approach to take is to use the JLCA and use this to convert the Java GEF Project to C#.
The resulting C# code should be analyzed to find the common problem areas that the JLCA cannot convert.
This information should be fed back to the Java GEF Project and that project should be modified to move the code that the converter find problematic behind some facade.
This will hopefully result in the main body of GEF being convertible and a small subsection being coded seperately in each project.
The lazer project can then be used to scan the C# code to make other minor style repairs such as correcting namespaces to pascal style naming.
This way GEF.net will stay in step with the design and take advantage of enhancements and bug fixes in the main GEF project.