Firebird 2.1 (version 2.1.0) is included by default in the Ubuntu 8.10 named Intrepid Ibex that was released on 30 October. To use it you might need this guide and also there is an repository with version 2.1.1 (recommended)
The Firebird 2.1.1 packages are now in ppa for Ubuntu Dapper, Gutsy , Feisty , Hardy and Intrepid Ibex
The guide for installing is located in the ubuntu wiki
[Update:Intrepid/Dapper builds are added and is now officially released ]
Here is the new guide for installing firebird 2.1 and flamerobin on the ubuntu hardy heron and can be used for other releases (gutsy/feisty/dapper/intrepid ibex)
