Delta Lake is an independent open-source project ( under Linux Foundation ) and is based on an open format . This has led to the community building connectors for delta from multiple engines - not just spark.
Out side of DBR, Delta Lake could be used in your spark code by adding the dependencies as mentioned
here In addition to this, there are connectors for other engines like presto, athena, redshift spectrum etc.
Also, you could natively query your Delta Lake with Scala and Java (via the Delta Standalone Reader) and Python (via the Delta Rust API)