The IDS 11.50.xC6 virtual appliance is now available to download here:
https://www14.software.ibm.com/webapp/iwm/web/reg/download.do?source=swg-informixfpd&lang=en_US&S_PKG=dl&cp=UTF-8
 
This can be a very useful environment to test IDS 11.50.xC6 features since IDS is pre-installed and configured. It is also a ready to use development environment - the tools you need to do development  are installed (CSDK, Data Server Drivers (incl JDBC, ODBC), PDO. Optim Data Studio. 
 
IDS 11.50.xC6 had several new features you can become familiar with using this virtual appliance. A good place to see a summary of the 11.50.,xC6 IDS features is from a write-up that appeared in the Informix Zone blog: http://www.informix-zone.com/node/912
 
Note that several different editions of the virtual appliance are created, all are currently based on SLES 10 SP2 and all are free.
 
The choices are:  32 bit vs 64 bit. VMware Workstation format vs ESX. Self-extracting executable for Windows or Gzipped tar file.
 
Make sure you download the right one.