Unless I missed something, none of these are capability-safe designs, whereas Sandstorm is capability-safe on the wire up to the edge of Capn Proto.

From the alternatives link "Sandstorm makes it easy to run your own server" and from their website "Sandstorm is a self-hostable web productivity suite". With that in mind, the alternatives seem reasonable.

what does capability-safe mean?

AFAIK Sandstorm was way out ahead of its competitors in this space; it was the only one HN ever deigned to pay attention to, at least.

Given that, and given that it's FOSS, then as long as the community is still interested in the project, the project should keep seeing development, regardless of the amount of time the original developers can put in. Even if that means a LibreOffice- or MariaDB-like fork.

> AFAIK Sandstorm was way out ahead of its competitors in this space

I think of those listed projects only few are backed by for-profit entities (like sandstorm itself). Cozy in particular seems very well funded (https://www.crunchbase.com/organization/cozy-cloud#/entity).

I also think the alternatives link is a bit misleading because those projects aren't really direct alternatives. I have investigated a bit in this space (for my personal hosting):

* Cozy is simply for a personal server for email/contacts. This is more like ownCloud. It's not meant for hosting internet facing websites.

* Sandstorm is sort of trying to build a Google Docs style portal. People share these docs with each other. This is why it has a "frame" around every doc/app. It's also not meant for hosting internet facing websites (by this i mean, it is not optimized for hosting your personal public blog).

* Bitnami is 1-click images for opensource apps. I am guessing their main user base is people who want to install a stack quickly. It's a glorified docker pull or curl.

* Cloudron is about running apps on a server. This is automation (ssl, backup, install/update etc) of what you would be doing today, if you have to setup a server and install apps like rocket.chat, gitlab etc. Cloudron uses docker for the apps. Yunohost does the exact same thing without docker.

> It's also not meant for hosting internet facing websites (by this i mean, it is not optimized for hosting your personal public blog).

It's an Intranet portal, essentially—like the one you get from setting up Apple's Server.app. But it could certainly be used to host an app that builds an Internet-facing website.

For example, you could launch an authenticated-users-only Wordpress instance on Sandstorm, to allow your team to collaboratively create a website. Then you'd install the Simply Static plugin in that Wordpress instance, and use it to shove a static-slug copy of the site out to a public web-enabled S3 bucket or wherever else you like.

In fact, there's probably a good nascent architecture involving Sandstorm + Minio + nginx where you use Sandstorm on the intranet-side, as a multi-product Content Management System for a public-facing site.