The Tarsnap client source code is available so that you can see exactly how your data is protected; however, it is not distributed under an Open Source license.

We invite you to review the client source code at github or the latest source tarball release.

While the Tarsnap code itself has not been released under an open source license, some of the "reusable components" have been published separately under a BSD license:

• The scrypt key derivation function
• The kivaloo data store
• The spiped secure pipe daemon

In addition to these, Tarsnap uses open source code and has a policy of contributing patches back to projects whenever possible:

• libarchive
• FreeBSD

Tarsnap has a policy of contributing each year an amount equal to its gross profits for the month of December to support open source software. Sponsorship recipients to date include:

• The FreeBSD Foundation (annually since 2009)
• BSDCan (annually since 2012)
• FreeBSD Developer Summits at BSDCan (annually since 2014)
• BSD Now (since May 2014)
• Simon Fraser University's Open Source Software Engagement Award (annually since 2014)