How does it work? Press the Pile button to store a link in your Pile bookmark folder. A scrollable sidebar gives you quick access to its content. Show and hide it by pressing the sidebar button in your toolbar. Differences to other “read it later”-like solutions

It’s small and fast.
It’s open source.
It doesn’t depend on cloud services. As long as you do not activate any bookmark syncing services (e.g. Firefox Sync), everything stays on your harddrive.
It doesn’t harvest your data.
It puts the focus on simplicity and interoperability. Pile won’t get in your way.

Keyboard shortcuts

Alt+⇧+P - put the current page on the Pile
Alt+⇧+S - open/close the Pile sidebar

To configure the shortcuts go to Tools/Add-ons, click on Extensions, click on the cogwheel on the top right, choose Manage Extension Shortcuts. Other features

Right-click on page - close the active tab after putting it on your Pile
Right-click on tab - put all unpinned tabs on the Pile and close them afterwards
Basic search functionality
You can move bookmarks in and out of your Pile using the bookmarks library. You can also re-position the Pile folder itself.
NEW: You can quickly clean up your Pile in one fell swoop. Just click on the trashcan symbol in your sidebar and select what you want to remove.