Flat File PHP+MD Blog Engines

Automad

A File-Based & Open Source Content Management System.

Technology : PHP
Templating : Built in
Formatting : Markdown
Website : http://automad.org/

Dropplets

FlatPress is a blogging engine that saves your posts as simple text files.

Technology : PHP
Templating : ??
Formatting : Markdown
Website : http://dropplets.com/

Feindura

Flat File CMS for designers

Technology : PHP
Templating : PHP
Formatting : HTML, Text and Markdown
Website : http://feindura.org/

Grav

In a nutshell, installing Grav is a matter of unzipping the file. It is fast, has sophisticated caching, and a light footprint for optimal performance.

Technology : PHP / YAML
Templating : Twig
Formatting : Markdown
Website : http://getgrav.org/

Monstra

An entirely new kind of CMS. Pack up your content, markup, and style. Leave the database behind. Making websites just got fun again.

Technology : PHP
Templating : Built in
Formatting : Markdown
Website : http://monstra.org/

Parvula

Simple CMS for developers, designers and clients with admininistration panel.

Technology : PHP
Templating : PHP
Formatting : Markdown (html if needed)
Website : https://github.com/BafS/parvula

Phile CMS

A Markdown File Based CMS

Technology : PHP
Templating : Twig
Formatting : Markdown
Website : http://philecms.github.io/Phile/

Pico

A stupidly simple & blazing fast, flat file CMS.

Technology : PHP
Templating : Twig
Formatting : Markdown
Website : http://pico.dev7studios.com/index.html

Singularity

A CMS in a Single PHP File

Technology : PHP
Templating : Nil
Formatting : Markdown
Website : http://christophersu.net/2012/singularity-cms-single-php-file/

Statamic