Justification.

Currently there is a huge mess of files and folders that start with a "." in any users home folder. There is no structure or policy on how applications should choose file and folder names for data that needs to be stored in users home directory. Additionally there is no established consistency between Gnome, KDE and most other applications. Gnome application have part of their configuration information in gconf folder and other part in a gnome subfolder. KDE applications have a complex structure under .kde/. And most other applications either have one file directly in users home folder or have their own dot-folder there.

Problems.

There are two major problems with current ad-hoc approach:

1. 
   Namespace pollution of users home space. In any desktop system "ls -al" in the home folder would be a very lengthy affair. Moreeven this namespace is folded - KDE and Gnome apps live in their own subfolders.
2. 
   Lack of structure in folders makes it much harder to properly understand their purpose. For example, if a user has misconfigured an application and would like to reset it to default settings, it currently could be hard to figure out how to do that. Especially without losing his data in that application.

Proposal.

I propose to implement a policy on where an application can store data and configuration information in users home folder. Such specification would be proposed as an extension for FHS, first implemented in Debian and then promoted for inclusion upstream and in other distributions.

Structure.

I propose a following structure for a users home folder:

• 
  data/appname/ - each application, that stores user data in application-specific format, will have to store this data into this folder. Only configuration information that is essential to load this data would be permitted into this folder (in hidden dot files). For example, Evolution could store emails and email access information here.
• 
  .conf/appname/ - each application that stores any configuration information whould have to store all of it in this folder. GConf will have to also store applications configuration info here. If this folder would be deleted, application must revert to default configuration, but still be able to fully access user data in data/appname/ or other, generic folders (below). For example, if .conf/evolution/ is erased, then on next start-up Evoution should still be able to access all email that is stored in data/evolution/ without any configuration wizards.
• 
  .tmp/appname/ - each application that would need to create temporary files that survive reboot, would put them here. These folders can be safely deleted at any time with no data or configuration loss. For example, Firefox cache information and Nautilus thumbnail cache would have to be here.
• 
  Desktop/ - the desktop folder, just like it is now
• 
  Media folders - (Documents/, Photos/, Videos/, Music/, ...) a suggestion of basic document structure for user to use or ignore. Applications dealing with particular media types would default to use files from such folders, but should also cope with working with any other folders on users choice. For example, a screensaver with slideshow function would by default use photos from Photos/, but will have to have a configuration option for user to change that setting.
• 
  Additionally I would propose having a .mounts/ folder where applications could mount user specific media and other mounts, such as FUSE. For example, FUSE could be used for automatic archive introspection.

Benefits

The main benefit for such system for me is twofold:

• 
  SBackup can be configured to exclude .tmp/ and .mounts/ by default thus saving significant space in backups.
• 
  A tool can be made to restore settings and/or data for specific applications in an uniform fashion.

So, any suggestions on the idea and on where this should be best discussed?