It was interesting to read the OSDN/BCG survey of open source developers, suggesting that most are professionals spending about a day per week on one particular project. Also interesting comparing that with our own experience, in which we do have a number of developers from the open source community but certainly not fitting the profile suggested by OSDN and BCG.
But on closer examination it's not that surprising. The population sampled was those who are named developers on various Sourceforge projects. And usually these people are the people whose baby it was in the first place. So it's very likely that these people will spend an hour a week on the project... and surprising they don't spend longer. If they surveyed us they'd find a bunch of full time developers working 40+ hours/week.
In my experience those who come to a project later spend much less time on it. Not too surprising. We have a handful of contributors who spend maybe 4hrs/week coding various segment. More significant projects therefore are unlikely to get off the ground. Our Storix project is a lot fo work for one person, even though the idea of it ahs generated much interest. So I've created much smaller projects (sometimes well-defined bugfixing or feature enhancements) such as the Swing front end to launcher, our command line management tool. This is a postive benefit, but also a very well-defined and medium-sized task.
I note that Miguel de Icaza says Evolution had 17 developers at its peak. So Jtrix, with its full time staff plus sundry others isn't doing too bad compared to a high profile, easily-understood, less ambitious project like that.