Explain in brief about Firebird and its necessity

Can this run on at x386, x64 and PowerPC, Sprac and other hardware platforms? Is it open source? What is multi-generational architecture and how can I get facility from it? Describe about its security. Can this support cross database query? Is there a tar. gaz distribution available? Can it be able to create backup copies without stopping database? Is Firebird connectivity available in PHP framework? What is the latest version available in Firebird? What is Read Only Deployments? Is it integrated with Sphinx? Thank You
