Client side JavasScript, all you need is a json document and a lot of heavy lifting on the client. Not a good solution for sites with a lot of content, but for

Client side JavasScript, all you need is a json document and a lot of heavy lifting on the client. Not a good solution for sites with a lot of content, but for the simpler ones... yeah. You won't get search, but still... For things like `popular posts`, you could probably have a task that queried your analytics data and generated a page. Once tasks are automated, it's not that much of a hassle. CMSs will still have much more to give though.