O comando aptitude search firebird2.5, no Debian, equivale a apt-cache search firebird2.5, no Ubuntu.
No Debian 8.2, o comando retornará o seguinte resultado:
aptitude search firebird2.5 p firebird2.5-classic - Firebird Classic Server - an RDBMS based o p firebird2.5-classic-common - common files for firebird 2.5 "classic" an p firebird2.5-classic-dbg - collected debug symbols for firebird2.5-cl i A firebird2.5-common - common files for firebird 2.5 servers and i A firebird2.5-common-doc - copyright, licensing and changelogs of fir v firebird2.5-dev - p firebird2.5-doc - arquivos de documentação do banco de dados p firebird2.5-examples - exemplos para Firebird - um SGBD baseado n i A firebird2.5-server-common - common files for firebird 2.5 servers p firebird2.5-super - Firebird Super Server - an RDBMS based on p firebird2.5-super-dbg - collected debug symbols for firebird2.5-su p firebird2.5-superclassic - Firebird SuperClassic Server - an RDBMS ba
