Eclipse has the very nifty "Compare with Local History" feature which lets you compare all files in the workspace against previous revisions. This is very useful to recover older versions even when they are not in a source control system, and it works because Eclipse keeps snapshots of all files when you save them.
Eclipse (by default) keeps up to one week, up to fifty changes and up to 1 MB of snapshot data per file.
On a Mac, you also have the Time Machine backups, which snapshot every file once per hour, keeping hourly snapshots for a day, daily snapshots for a month, and weekly snapshots until you run out of disk space.
Is there an Eclipse plugin to make use of the Time Machine data for local history beyond the copies that Eclipse stores?