Did you ever...

work on a craft for hours and kerbal crashed making all your work for nothing ?
used the undo hot key but it didn't do what you expected and now hard work is again for nothing ?
want to have an older version of your craft but never saved it ?
want to group up your crafts in the load menu ?

Well we got the answer for your troubles. Presenting CraftHistory.

Saving your craft file after every change of the craft or periodically.

If you don't want your crafts to be saved and only want to use the categories feature of this mod you can simply disable it.

Right clicking will open the settings menu where you can chose between 3 different methods when to create a history entry.

Left clicking will open the categories your current craft is in.