Sequel comes with a command line program named sequel, which is usually referred to as bin/sequel.
With the standard usage of bin/sequel, you get an irb shell with the database you specify on the command line preloaded in a constant named DB.
You can use bin/sequel to run Sequel's Migrator, similar to rake db:migrate in Rails.
You can also use bin/sequel to dump the current database schema in migration format, which is useful if you are starting to use Sequel with an existing database.
Finally, you can use bin/sequel to copy one database to another, even for different database types, so it works like a local version of Taps.