Slic3r PE 1.40.0 comes with a major re-work of the way configuration presets work.
There are three new features:
+ A two-tier system of presets being divided into _System_ and _User_ groups
+ Configuration snapshots
+ Configuration updating from the internet
## System and User presets
- _System preset_: These are the presets that come with Slic3r PE installation. They come from a vendor configuration bundle (not individual files like before). They are **read-only**– a user cannot modify them, but may instead create a derived User preset based on a System preset
- _User preset_: These are regular presets stored in files just like before. Additionally, they may be derived (inherited) from one of the System presets
A derived User preset keeps track of which settings are inherited from the parent System preset and which are modified by the user. When a system preset is updated (either via installation of a new Slic3r or automatically from the internet), in a User preset the settings that are modified by the user will stay that way, while the ones that are inherited reflect the updated System preset.