Using PieCrust is mostly a matter of editing text files.
The application’s code itself, of course, is a bunch of text files. It’s standalone, so you don’t have any dependencies to install.
Your website will also be mostly text files. Configurations are written in YAML, a simple human-readable syntax. Templating is handled by default by Twig, with a syntax similar to Jinja or Django. Text formatting is done by default through Markdown, which lets you write page contents the same way you would naturally write an email.
If you don’t know any of those names I mentioned, don’t panic! Keep reading, you’ll see it’s easy.
PieCrust only requires a web-server running PHP 5.3+ for dynamically rendered websites. If you bake your website, however, all you need is a web-server that can serve HTML files, and that’s by definition any web server! You can’t make it simpler (although of course you’ll need some computer with PHP somewhere to do the baking in the first place).