Which feature in SQL Server and Azure Synapse Analytics lets you run T-SQL queries against external data stores and makes those external sources appear as tables in a SQL database?

Sequel is a simple, flexible, and powerful SQL database access toolkit for Ruby. Sequel provides thread safety, connection pooling and a concise DSL for constructing SQL queries and table schemas.

Not all of these releases were tagged on GitHub and none of them have release notes on GitHub. Releases prior to 0.5.0 were not documented (although some were tagged on GitHub).