Ruby gem that binds SQLite to Ruby; the driver used by Active Record for SQLite connections. Since version 1.6.9 it accepts a `default_transaction_mode` initializer option that Rails passes through from database.yml. Stephen Margheim landed a fair, non-blocking busy-handler implementation on the gem's main branch that replaces SQLite's native C busy_timeout with a Ruby-level Sleep-based callback, and plans a Rails PR mapping the database.yml `timeout` key to it.