I'm not sure I understand all the requirements:

a) should there be a single erlide project that refers to all the applications in the lib directory?
b) or do you want a separate project for each application in lib, without needing to manually create a project for each?

c) is the '_build' directory a sibling of 'lib'?
d) or is there one '_build' per application in 'lib'?

For (a), you can create a project in the top directory and use the "discover paths" button on the second page of the wizard. It might not discover everything, some manual tweaking might be needed.

For (b), we don't have a "multiple projects import", it's probably not difficult to add.

For (c+a) and (d+b), it's just a matter of configuring the project to use _build instead of ebin and disable the automatic build in eclipse (in the 'project' menu).

(c+b) might work, but the _build dir is outside the projects' area and I'm not sure if Eclipse likes that.
(d+a) is tricky, we don't have support for that yet.

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