In reply to David.

I am going to give Grav a try to see how it is. I used another flat-file based CMS before: BlogEngine.net for Windows platform, and I would like to point out that it is not easy to migrate from WordPress to a flat-file based CMS, and vice versa, so once you decide to use one CMS, you should stick with it. Even though Grav has a WordPress plugin to transform your posts to Grav pages automatically, you still need to manually migrate all your media files under Grav and make sure all links are correct. It could be a big hassle for a large web site.

The biggest advantage of flat-file based CMS is that it is very simple and easy to use, and especially when you move your site to a different hosting company. Since there is no database involved, all you need to do is to copy and paste the entire website folder to the new hosting platform.

Again, thanks for sharing the information and I will install it on my Windows hosting platform to play with it.