1) Dating material & knowing when content is updated.
We actually do keep version info in the rachel-index.php file for each module. And for the technical we expose that information here as part of our JSON api.
We used to use dates as version numbers (and many modules still do), but we've been moving to two-part semantic versioning. This was primarily because some content doesn't get updated often (like, say, an algebra course) and dates made them look "old" when in fact they were still current.
1.1) The Rachel Plus preview "about" page says "SEP 2013 Version." Does that date relate to the "Rachel OS" version?
Um, the previews are a bit out of date Unfortunately updating RACHEL functionality usually takes precedence. But to answer the question - no, that date tag at the bottom of the preview page doesn't really pertain to any particular part of the system -- it's been removed from the new RACHEL builds.
1.2) How does a user know the content date of their modules because this is not displayed on the main page? (Need to look at the files?) I suggest adding a date in each module "window/box" as viewed on the main page.
1.3) How does a user know when modules are updated? I would suggest adding a date to the summary view and detail page of the module download page.
You can see chick info on the RACHEL-Plus admin "version" page if you click "Check For Updates". We try to keep extraneous information on the front page to a minimum.
1.4) Ex. the Radiolab preview only has material to 2013 but their website is still adding new content.
Indeed, given resource constraints we don't get to update as often as we'd like. We are always happy to accept updated submissions, however!
2) Do you have special permission to distribute some content? (I presume so.) Could you place copies of these approvals in a public place? (Ideally linked to the module download page.)
In some cases, yes, though those are generally not exposed to the public, and are reserved for special orders. Going forward each module should include it's own licensing info when updated. Keeping a list on the "about" page as we did is no longer feasible. The preview page is outdated -- the new page in currently shipped versions says "The educational content included in RACHEL are available under a variety of licenses that allow free usage under a variety of terms. Please check each individual module for details. All content is available for free online."
I didn't put that module together, so I'm not sure of the arrangement. However if any of the publicly available downloads is not licensed for redistribution, they should be removed. In most cases it's probably just a matter of the terms not being included in the module as we only recently started doing that. I think a lot of the gaps are the result of trying to keep a volunteer group effort organized
3) Since some installations may have internet access, should online links be provided to the content provider on the main page?
Our primary use case is in non-connected environments, so we try to avoid links to the outside world for the most part - otherwise it just looks "broken" to people who may not understand the distinction between online and offline.