[tigerente]

From their website, it seems that tarsnap can't be counted as OSS: "The Tarsnap client code is built around the open source libarchive archive handling library. While the Tarsnap code is not distributed under an open source license..."

[jgrahamc]

Here's the source code: https://www.tarsnap.com/download.html

This is the license:

Unless specified otherwise in individual files, the contents of this package is covered by the following copyright, license, and disclaimer:

Copyright 2006, 2007, 2008, 2009, 2010, 2011 Colin Percival All rights reserved.

Redistribution and use in source and binary forms, without modification, is permitted for the sole purpose of using the "tarsnap" backup service provided by Colin Percival.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

[arethuza]

My reading of that is that you aren't allowed to redistribute any modifications or use it for anything other than accessing the tarsnap service.

So not really open source software in any sense that I understand.

[NB My comments is not intended as a criticism of tarsnap or Colin's licensing policy - he wrote it so, in my book, he can license it any way he wants.]

[sigil]

> Redistribution and use...without modification, is permitted for the sole purpose of using the "tarsnap" service.

(emphasis mine) This sounds like there are no restrictions on distributing modified source / binaries.

[cperciva]

Quite the opposite: No permission is given to distribute modified versions, so you're not allowed to do it.

[bnr]

It's open source, allright. Free Software is the term you are looking for.

[throwaway2048]

Free to distribute is one of the fundamental defining things about open source [1]. Lets not water it down to the point of meaninglessness like words like `open' currently are.

[1]http://opensource.org/osd

[graue]

The Tarsnap client code isn't Open Source, but the source code is available, which means it can be audited.

s1kx's caveat ("Of course you will have to trust CloudBerry not to put a backdoor in their Software") therefore doesn't apply (as strongly, anyway) to Tarsnap.