I am about to jump from Windows to Linux with a test server installation. I
have total freedom to pick a Linux distro to start with but I need help
deciding which to choose.

Unfortunately the two apps I definitely want to run on this machine are
Firebird and Kylix. I understand they have conflicting requirements in the
sets of distros they work on but I need to solve this problem at some
point. (If I have to I'll start with Firebird and then make changes to get
Kylix working.)

Any guidance on what is a good Linux version to use with either Firebird or
Kylix would be appreciated.