Aliro was released around 2008, along with my book on CMS Framework Development. The code is now wildly out of date (and the one book review seems a bit unfair - time has inevitably passed). But a number of the ideas are actually still relevant....
One feature was the role based access control (RBAC) service. That still exists, largely unchanged, in the Remository file repository extension. It provides flexible control over who can access which folders in the repository. It's easy to use and very effective.
Another feature was a flexible caching system. The most significant aspect was the caching of objects. Caching database queries is pointless - the database does it better. Caching pages often creates problems for dynamically created pages. But caching objects that are costly to create is the sweet spot for caching.
A less fundamental but very useful feature was the ability to run a SELECT database query and have a specific class populated and returned. That allows a direct move from the database query to an object that has not only data but also behaviours.
If you would like to see the old Aliro code, you can clone the git repository at https://forge.bsr.cloud/martin/Aliro.git
It's a shame Aliro was never able to get enough traction to take off. It might have avoided some of the problems that are dragging down Joomla, and are now beginning to afflict Wordpress. Who knows!
I'm thinking about updating the code. But it would be a big job. I have a number of other things in mind, so I don't know if it will ever get done.