./configure --with-mysql --with-interbase --with-apache=../
cd ../
./configure --activate-module=src/modules/php3/libphp3.a
make

[..skiped..]
modules/php3/libphp3.a(interbase.o): In function `_php3_ibase_error':
/usr/home/kostich/rapache/apache_1.3.6rusPL28.13/php-3.0.9/functions/interbase.c
(.text+0x66): undefined reference to `isc_interprete'
modules/php3/libphp3.a(interbase.o): In function `_php3_ibase_commit_link':
/usr/home/kostich/rapache/apache_1.3.6rusPL28.13/php-3.0.9/functions/interbase.c
(.text+0x150): undefined reference to `isc_commit_transaction'
/usr/home/kostich/rapache/apache_1.3.6rusPL28.13/php-3.0.9/functions/interbase.c
(.text+0x178): undefined reference to `isc_rollback_transaction'
modules/php3/libphp3.a(interbase.o): In function `_php3_ibase_close_link':
/usr/home/kostich/rapache/apache_1.3.6rusPL28.13/php-3.0.9/functions/interbase.c
(.text+0x1b3): undefined reference to `isc_detach_database'
modules/php3/libphp3.a(interbase.o): In function `_php3_ibase_close_plink':
/usr/home/kostich/rapache/apache_1.3.6rusPL28.13/php-3.0.9/functions/interbase.c
:331: undefined reference to `isc_detach_database'
modules/php3/libphp3.a(interbase.o): In function `_php3_ibase_free_result':
/usr/home/kostich/rapache/apache_1.3.6rusPL28.13/php-3.0.9/functions/interbase.c
(.text+0x230): undefined reference to `isc_dsql_free_statement'
modules/php3/libphp3.a(interbase.o): In function `_php3_ibase_free_query':
/usr/home/kostich/rapache/apache_1.3.6rusPL28.13/php-3.0.9/functions/interbase.c
(.text+0x299): undefined reference to `isc_dsql_free_statement'
modules/php3/libphp3.a(interbase.o): In function `_php3_ibase_free_blob':
/usr/home/kostich/rapache/apache_1.3.6rusPL28.13/php-3.0.9/functions/interbase.c
(.text+0x2eb): undefined reference to `isc_cancel_blob' 

etc ...