In a discussion on the libssh2 mailing list, the founder and maintainer of the libssh project got involved. The actual discussion is not what I want to talk about here, but something he touched on in one of his mails:
"I think a bit of competition in open source is fair and leads to innovation"
Recall that there are only two existing SSH libraries written in C that are free and open. These two libs have roughly the same features, the same goals and a lot of other similarities.
So, does it help open source projects to have an identified and known competitor to compete against and to try to steal users from and to try to outperform in other ways? Is there any research done that proves this theory?
Or is it just so that we have a number of developers with a certain amount of time, and if we divide those in two or more groups we therefore make sure that neither is advancing as fast as they could if all those persons would participate in the same project? Open Source projects are so often driven and developed by volunteers, and within a given area (say people interested in a SSH library) there is only a given amount of people and to make the best use of that limited set, wouldn't it be better if they all would work together in a single project?
Would OpenBSD, NetBSD and FreeBSD have been better off by not having split up? Would KDE and GNOME have reached further today if they had been a united project?
I don't know the answers here, and most probably the answer isn't very clear or binary applying to all cases anyway as I bet all situations are slightly different and thus should be considered separately.
In the history of FOSS, many forked projects end up getting merged again but we don't often see two independently created projects merge. I guess the Compiz and Beryl fusion is an exception. I think the sense of "my pet project" is often too strong, not to mention that different licenses and different development cultures make mergers hard to take place.
Look, I'm not really advocating that libssh2 and libssh should merge at this point. I'm just playing with the idea and trying to see the issue from different angles.
There are of course several things that would speak against projects to merge: different views on what licenses that are suitable, religious things such as how to indent source code or what build system to use. Quite possibly also other social aspects: development and team "culture" and behavior and why not just the "Not Invented Here" syndrome - it isn't always that easy to give up what you made yourself or to appreciate someone else's work.