Historically, the rsyslog source tree contains a lot of seldomly-used and exotic modules. Some of them even don't work at the moment. I kept them inside the tree so that they could serve as a sample for folks trying a similar things. However, there has been discussion on the rsyslog mailing list that all of this clutters up rsyslog and makes it a bit hard to understand which modules are well maintained, which are not, and which actually do not work or just serve an exotic border case.
I think these concerns are valid. As a consequence, I will go through the codebase and remove what is not in actual use. I will keep contributed modules which are only occasionally maintained, but I will move them to their own directory (./contrib) so that folks more easily see this is not a project-maintained plugin. Actually, we gain clarity from this move, but we don't loose anything: if someone decides to base some new code on the then-removed code, it's still available in older git versions. So it can still be used as a template. Besides clarity, getting rid of the cruft also eases the work of maintaining the source tree and hopefully also releases work of distro packagers.
To get you an idea of what kind of things I will remove: there are some java programs inside the code, which were used in early versions of the testbench (around v5). They are no longer in any use at all. There is omoracle, which is orphaned for quite some while, and does not work any longer since the days of v6. There is obviously no interest in this plugin, otherwise folks would have stepped up and maintained it during the past 3 or 4 years that it does not work. There is sm_cust_bindcdr, which was done as part of a custom project. While we asked for permission to include this into the project (and got it ;)), the actual module is so specific that it is extremely unlikely someone else can use it. We just integrated it as an example. These kinds of things we will remove.
Note that this step probably also helps us in moving rsyslog as whole over to ASL 2.0, which is our long-term goal since long. Some of the things now being removed (omoracle, for example) would be problematic, as they are under GPL and we cannot contact the author any longer. This is a nice additional benefit of the cleanup.