One of the reasons I've been a bit quiet lately (apart from an unexpectedly high - and tiring - workload) is that much of my free time has been absorbed testing new versions of Zyn. As well as the main branch which is receiving a great deal of under-the-hood work, there is now an alternative development. This is not a fork as such, and moves are being made to fold it's best features back into the mainstream.
This version 'Yoshimi' is currently Linux only, and works only through Jack. The developer decided to strip out all non-essentials so he could get to the core of Zyn's problems. A fascinating issue that cropped up was something I'd never heard of before - dnormals - which in a nutshell happen as a level decays slowly and approaches but doesn't quite reach zero. In this situation the CPU switches to a higher precision, and slower, mode. Not only is it slower but the actual switching process takes time and screws up time scheduling.
So detailed has the work been done on this, that I was able to run Yoshimi for over 20 hours continuously, with lots of swapping, editing, reloading of voice patches with out a single crash. OK, there were some xruns on editing, but who is going to try to change internal prameters by hand while actually playing! Total processor usage has dropped significantly and I am able to run all of my most complex voices now on fast musical tracks without a single xrun or freeze.
There was some argument between developers at one point, but this seems to have been smoothed out. The guy who has done all this work on Yoshimi is clearly a very talented programmer, but so is the lead developer for Zyn. This is often not a good combination
There is a side-plot to try to move Zyn away from FLTK on to a mainstream GUI - KDE/qt looks like being the one of choice, but this is very early days yet. the main focus is getting Zyn. fully RT safe, and cross compatible. Let's not forget that all this is being done by people in their free time just for the love of music!
For the time being, Yoshimi is my synth of choice, and anyone wanting to look at it can find the latest version at:
http://www.graggrag.com/?q=node/19This is source code so you will need to know how to compile it. Instructuctions are given, but not ecaxtly hand-holding!