I have been a user of Gentle.Net since version 1.1. I have found it excellent for my purposes and sad to see it fold.
Would it be possible to have the documentation available on line for all the current Gentle.Net users.
Yes, I am planning to restore some kind of access to the documentation. I do have database backups of Confluence and everything in it, but due to migrating the server to Windows from Linux it needs to be reinstalled from scratch. And as is typical for Java apps, this is not at all easy to do. I am still pondering whether Confluence is really needed or a simple PDF or HTML export would work just as well, but something will certainly come back online.
Until then, please have a look inside the Documentation folder of the Gentle release archive. It contains a PDF export of all relevant pages from Confluence and thus most if not all of the original documentation.