There's no AD integration software "stack", which is smaller than twice the size of tinycore itself...
At this stage I place more importance on finding a reliable method consistent with the objectives of simplicity and convenience. This may sound like heresy, but years of experimentation suggest that the first concept is rarely identical to a finished result; it tends to be refined once it is working.
Likewise-Open is interesting...
I can see the attraction of this product. From browsing the website there are many references to its use in conjunction with Microsoft Active Directory (AD) e.g.
...joins Linux, UNIX, and Mac OS systems to Microsoft Active Directory to securely authenticate non-Windows users with AD credentials.
[...]
You can standardize on Microsoft Active Directory without losing the flexibility to choose other operating systems.
Do you know whether Likewise-Open only works in an AD environment? If it is mandatory I may have to find an alternative. Zentyal positions itself as
Zentyal Linux Small Business Server
Broadly, this is equivalent to Microsoft Small Business Server. Zentyal does not require AD, however it is optionally able to integrate with AD if necessary.
Now the tricky part: To have a true multiuser system you need at least a login manager and for pam_lsass.so (the likewise open authentication module) I believe you'll need Linux PAM enabled in the system (same if you use Samba, there it's pam_winbind.so), which means recompiling busybox against PAM. Finally you would have to change the inittab behaviour of tc to spawn the login manager instead of a console/autologin.
These may represent the potential deal breakers. One of the primary attractions of Zentyal is the packaging together (as optional functional profiles or individual modules) the most common network services.
Zentyal can act as a Gateway, Infrastructure Manager, Unified Threat Manager, Office Server, Unified Communication Server or a combination of them.
Ally with this a web GUI through which they are managed in an integrated manner and it is evident that it is suited to circumstances where time, funds and brains are limited. It conducts most of the 'heavy lifting' for the administrator. The potential deal breakers mentioned above are not tasks to be undertaken lightly; they may be beyond the experience of many users. They re-introduce 'heavy lifting' elements which detract from the objectives of simplicity and convenience.
As we may be the first to explore central authentication and provision of authorized resources, I can foresee some reluctance from the wider TC community. It is possible that current users may see little value in this type of research as it is outside the mainstream way in which TC is currently being used. Conversely, the partnering of two innovative OSS offerings (TC and Zentyal) may open doors into new areas (clubs, societies, home networks etc) that previously required higher levels of expertise and/or financial outlay for licences. Additionally, they appear well suited to the type of hardware that might be available in such non-profit organizations.
Are the potential deal breakers actually such? Are they able to be handled in a way that is simple and convenient and also in keeping with TC?