> Assume that your own application will take around a year to write/test > before deployment. Do you wait to start that work until after the > release of the OS and libraries you will be using, develop on something > you know is wildly different, or do you try to use something as close as > possible, knowing that backwards compatibility isn't taken very > seriously in the Linux kernel and distribution world? Why are you waiting for the next RHEL release ? RHEL releases are sufficiently infrequent and maintained for a long enough period, that I don't see any reason to wait for the next release. RHEL 5 is out now. Its going to be maintained for a good few years to come. If I was interested in beginning a project using RHEL, why would I be looking to RHEL 6 now ?. Now the part of your argument that does make some to me is you have released your RHEL5 product, you want to spend some effort making sure you are RHEL6 ready before it comes out ? However, if you are a RH custom, you will (I think) get access to the beta releases prior to release, so you will be able to do this with 'RHEL6-beta', which will still be closer to RHEL6 than any Fedora release will be. If you are not a RH custom (so replace RHEL with Centos/SL in all the above) then you will need to find another way, I'll give you that. Either use Fedora, custom installation of the newer libraries on your current system, or well just wait until the release comes out, and update your product at a slightly later date. Chris