Connection pooling for differing databases?

Hi all,

I'm wondering if there's a tool like pgpool that can provide a single
origin point (host/port) that will proxy/direct connections to the specific
servers that contain the db needing to be accessed.

For example... lets say we had two databases: db1.company.com:5432 and
db2.company.com:5433

Db1 has the database: env1
Db2 has the database: env2

Is there a tool that will accept connections, so that when users connect
they see there are two databases they can go to: env1 and env2.

If they choose to connect to the env1 db, it routes all traffic to
db1.company.com:5432 and if they choose env2 it routes them to
db2.company.com:5433

Of course there would have to be some requirement such as the databases on
any given server cannot have name collisions with database names on another
server, etc. Is there a way to do something like this?

Thanks,
Arjun