The aiki framework stores everything in the database. If everything means everything, the result will be a great leap forward in some areas and a performance hit in other areas.
Storing everything in a database is an approach I used for a couple of frameworks I wrote for projects years ago. Disk speed and memory limited the overall performance. Offsetting that was the lack of data to store. Web sites back then where a little bit simpler than today. Database usage for modern web sites is a bigger issue.
Early web sites rarely rarely catered for multiple languages. Today multiple language support is just a normal feature of all web site software. Adding that extra level of data selection is difficult in a file system because you have to create multiple directories or rename files. The equivalent in a database is really easy. PHPmyAdmin users just hit a few buttons in the table structure page. you can change your SQL easier than you can change code to access files.
The argument against storing things in databases is usually based on performance or a specific limitation of a specific database. If you use one of the major databases and keep it up to date, the limitations went away a couple of years ago. That leaves performance. For hosted Web sites, the performance limitation is often imposed by your host taking shortcuts in the database area. They might give your Web server a mass of resources then squeeze your database onto an overcrowded server.
When you store everything in a database, you have to give the database as much care and resources as your Web site. You need the same resource monitoring on your database as you use on your web site. You need as much control. Some sites can use one database to support ten Web servers but not many. A modern full feature Web site needs about the same resources for the database as used for the rest of the web site.
Download the framework at aikiframework.org.
There are few demonstration sites for the framework and some of the sites are still in transition from older technologies.
There is no content management system based on the framework chick makes it hard to see the complete range of possibilities. To work out how far you can stretch aiki, you would need a demonstration site showing all the features you need then you would need administrator access to see how much was contributed by aiki compared to local development by the Web developers.
When there are more sites using the framework and more documents listing the implementation work, you will have more options to evaluate aiki for future projects.
Aiki is designed to let you develop a Web site in hosting accounts where you have no access to the file system. Unfortunately that type of hosting is usually the worst at hosting databases. Aiki has more potential where you store many small related sites in the same database. Aiki would be a potential alternative to the Drupal Domain module.
I am interested in hearing from people who have implemented two similar projects in aiki and another framework or a CMS.