AAApache ArrowApache Software Foundation · Data catalogs & formatsIn-depth entryLanguage-independent columnar in-memory format and libraries that let DuckDB, Polars, pandas, Spark and databases exchange tables without copyingApache-2.0Open sourceFreeLocalNov 2, 2026
APApache ParquetApache Software Foundation · Data catalogs & formatsIn-depth entryOpen columnar file format for analytical data with compression, encodings and statistics, readable by nearly every data engine and libraryApache-2.0Open sourceFreeLocalNov 2, 2026
DLDelta LakeDelta Lake project (Linux Foundation; created by Databricks) · Data catalogs & formatsOpen table format with a transaction log over Parquet files, created by Databricks and hosted by the Linux Foundation, with Spark, Rust and Python implementationsApache-2.0Open sourceFreeLocalSelf-hostedNov 2, 2026