ZBack is a file browser to wind the clock back in time via ZFS snapshots

ZBack is a simple file browser that understands ZFS and allows you to browse snapshots by viewing them as points on a timeline. The browser understands two points in time: "now" and "then". "now" is the current state of the filesystem; "then" is a snapshot. Going counter-clockwise from the upper left, the components of the window are:

• A drop-down list for choosing which ZFS filesystem (mountpoint) to browse. If there is only one, it will be preselected and the list will be disabled.
• A drop-down list with entries for each directory in the path leading to the directory currently being viewed. If you want to go up the file hierarchy, just choose the appropriate parent.
• A scrolling list with the names of all of the files in the current directory.

There are four display styles for entries in the file name list:

• Crossed out: existed then, but deleted now.
• Green: exists now, but not then. It's a new file.
• Bold: exists both now and then, but it has been modified since then.
• Normal: exists both now and then, and is the same in both times.

At the bottom of the window is a slider for choosing "then". At the far left is the beginning of time (the oldest snapshot), at the far right is "now". The right side of the window is dominated by a tabbed pane. The four panes are:

• Content: the contents of the currently selected file.
• Diff: the differences between two versions of the file (either "then" and "now" or "then" and "just after then")
• Preferences
• Help

The preferences you can change are:

• Only use mods in timeline: If not checked, every snapshot will correspond to a point in the timeline. If checked, the only snapshots with points in the timeline will be those where either the currently selected file or the currently selected directory are modified. This lets you easily ignore times when there was little activity.
• diff against following version: for text-ish files, ZBack will automatically run "diff" between versions of the file. If this box is checked, the diff will be between the versions then and just after then. Otherwise the diff will be between then and now. The following text box lets you specify arguments to be passed to diff.
• Snapshot: ZBack can manage the automatic taking of snapshots. It does this by inserting a "zfs snapshot" command into your crontab. "Go" builds (or removes) the command based on the other options.