Decided to install php5 and firebird 1.5 on Debain
very easy

do the following edit

# vi /etc/apt/sources.list

add these two lines to the file

deb http://people.debian.org/~dexter php5 sarge
deb-src http://people.debian.org/~dexter php5 sarge

save and exit :wq

then do a
# apt-get update

then install all the modules you need
use this command to check whats available
#apt-cache search php5

then install what you want
#apt-get install php5 php5.0-firebird

it installs a few things like apache etc if you havent already got it
installed.

then restart apache
/etc/init.d/apache2 start

you might want to remove php4 beforehand if you have it installed

it seems to work fine big thank you to the guy who maintains this
package! if you are on here. Debian ROCKS.