Yes. Efficient storage of all historical versions of a file is built into the core SpiderOak algorithm. This enables you to access any historical document from a specific point in time, from any machine in your SpiderOak network.
If a file is ever damaged or deleted or accidentally overwritten, you will always have the option of downloading an earlier undamaged version. The number of existing versions is listed next to the file name in the SpiderOak "View" tab. When this file is clicked on, a list of existing versions will appear on the right, organized by time created. Select the version you want to download and SpiderOak will re-download that version onto your computer.
SpiderOak saves storage space using intensive data de-duplication. In this way, SpiderOak can often keep all of the historical versions of a file, using about the same amount of space that would be required to store only the most recent version.