In 2016, Wolfram took a big step from the user's perspective and made the Wolfram Workbench freely available. Until then, the IDE for creating full-fledged Mathematica packages was only available to Premier users. Making the primary development tool freely available was one of Wolfram's great decisions because it helps to spread the language. This makes it more widely applicable, and it supports the people who write packages as well.
With Workbench freely available, why would it be vastly beneficial to have access to its sources? Because it is a great resource for developers to learn how to use advanced technologies like JLink, to see how it can be used to interact with Mathematica. One recent similar example was the publication of GitLink generously donated by John Fultz. Inspecting his code gave us so many ideas, especially how to extend the argument completion for Mathematica.
In the case of Workbench, there is so much more we can learn from
These four points are just the ones that came to mind. I'm sure there is a lot more to it.
Besides using the code as a resource for learning, there is an additional point: People would be able to track down bugs by themselves. Even if we have only a few developers who use WL and are fluent in Java, the chances are good that they start a debugger and track down an issue when something went wrong. In a best case scenario, Wolfram gets high-quality patches for free.
All that being said, I would be delighted if Wolfram would consider making the Workbench Eclipse plugin code public. What does the community think about this idea?
Great idea. Perhaps there could be an open-source community to maintain and extend the code, similar to what Apple did with Swift.
This is a great idea. I fully support it.
Thank you for posting this idea. We are discussing this internally.
Thank you, Stefan, for taking this into consideration. I know this would be an unbelievably generous present to the community and the chances are that it might not happen. In any case, even discussing this internally and listening to the community is incredibly kind. I hope you keep us posted on the outcome.