Update: A new VPS control panel
With all of this excitement about Stallion (which looks great, btw), I figured I should give an update on my control panel.
I'm making pretty solid progress; most of the core functionality for OpenVZ and KVM is there (Xen is on the way). There's also still some core functionality that does need to be developed, such as integration with WHMCS, among other things.
The frontend is minimalistic, quick, and responsive, as it makes heavy use of AJAX and client-side templates. One aspect I think will be appreciated about it is its ability to be themed/skinned. It's trivial to modify either the CSS or the templates themselves (or both). It uses LESS so you can change the entire color scheme in a single place (although in production, the less would be compiled to CSS). I'm also trying to make the frontend very "usable", e.g. sorting on any column in tables, good search features, etc. All that said, keep in mind that I'm not a designer, so the UI is pretty plain (but maybe some people like the minimalism ).
One side effect of the AJAX frontend is that it now has a nice, fully-functional API that it can expose. Overall, I've been developing the control panel in a very "correct" (and thus secure) way: tokens prevent CSRF, client-side templates prevent XSS, prepared statements for all database interaction, etc. I wish this stuff went without saying, but it's worth noting.
One more thing to note: it still needs a name. Suggestions are welcome. Also, if anyone has suggestions or criticism as far as the UI or functionality goes (or anything else really), I'll take that as well.
If any providers would like to work with me in testing, and potentially using it, let me know. It could be a good opportunity to get a nearly custom-tailored control panel without much risk.