There are only two open source libraries for SSH that I am aware of. At least that are at the fundamental layer, written in C.
I researched the SSH library market years ago when I stuck with libssh2 as the one I thought was most promising, and since then I and others have taken it much further. The lib that I didn't go with at that time, confusingly enough named libssh, recently came out with a new release.
Since there is now clearly two active open source SSH libraries it feels like we should help our users and potential newcomers by explaining how our projects and libraries differ. As a little teaser: one of the libraries turned out more than twice as fast as the other in my test...
While I admit to not having actually used libssh for real, I've read the docs and I've tried it a little bit. My take at a comparison is now online at:
I will highly appreciate your feedback and additional things that differ between the two! The list isn't really much to boast about as it currently looks!