Computing and digital systems

Apache Griffin

Apache Griffin was an Apache Software Foundation open-source data quality platform for big data, batch and streaming, built on Hadoop and Spark. Entered incubation 2016, graduated November 2018, retired to the Apache Attic in 2025 (ATTIC-246); final release 0.6.0.

Apache Hadoop

Apache Hadoop is an open-source framework for storing and processing large data sets across clusters of commodity computers, combining HDFS storage with MapReduce processing and YARN resource management.

Apache HBase

Apache HBase is an open-source distributed NoSQL data store modeled after Google Bigtable, running on HDFS. Started in 2006 at Powerset, it powers high-throughput uses like Facebook Messages.

Apache Hive

Apache Hive is an open-source data warehouse system built on Apache Hadoop that queries very large datasets using SQL; developed at Facebook from 2007 and open sourced in 2008.

Apache Hop

Apache Hop (Hop Orchestration Platform) is an open source, metadata-driven data integration and orchestration platform forked from Pentaho Kettle in 2019, an ASF Top-Level Project since January 2022, with 250+ pipeline transforms and Beam/Spark runtimes.

Apache HTTP Server

The Apache HTTP Server, commonly called Apache or Apache2, is a free open-source web server developed by the Apache Software Foundation, begun in 1995 as patches to the NCSA HTTPd server.

Apache Hudi

Apache Hudi is an open-source data lakehouse table format providing atomic upserts, deletes, and incremental change streams over Hadoop-compatible and cloud object storage, developed at Uber in 2016.

Apache Iceberg

Apache Iceberg is an open table format that turns files in object storage into versioned, ACID-compliant tables, originated at Netflix and now an Apache project.

Apache Impala

Apache Impala is an open-source MPP SQL query engine in C++ and Java for Hadoop, Iceberg, Kudu, and cloud storage, developed at Cloudera, an Apache top-level project since 2017, latest release 4.5.3.

Apache InLong

Apache InLong (应龙), formerly TubeMQ, is an Apache top-level data integration framework from Tencent supporting ingestion, synchronization, and subscription; incubated 2019, renamed 2021, graduated 2022-06-15.

Apache JMeter

Apache JMeter is an open source, 100% Java application for load and performance testing, originally written by Stefano Mazzocchi for testing Apache JServ and first released in 1998.

Apache Kafka

Apache Kafka is an open-source distributed event streaming platform, developed at LinkedIn and maintained by the Apache Software Foundation, that captures, stores, and processes event streams in real time.

Apache Kafka protocol

The Apache Kafka protocol is Kafka's binary TCP wire protocol: size-delimited request-response pairs, ApiVersions negotiation since 0.10.0.0, KIP-482 flexible versions, and KIP-896's removal of pre-2.1 API versions in Kafka 4.0.

Apache Kudu

Apache Kudu is a distributed columnar storage engine for the Hadoop ecosystem, born at Cloudera and a top-level Apache project since 2016, combining fast inserts, updates, and MVCC/Raft consistency with Parquet-comparable analytics.

Apache Kylin

Apache Kylin is an open source distributed OLAP engine originating at eBay (2014) and an Apache top-level project since 2015, using cube pre-computation for sub-second SQL queries on trillion-record datasets; Kylin 5 adds internal tables, Gluten-ClickHouse native engine, and Kafka streaming-batch fusion.

Apache Kyuubi

Apache Kyuubi is a distributed, multi-tenant Thrift JDBC/ODBC SQL gateway (serverless SQL on lakehouses) built on Apache Spark and other engines like Flink, Trino, and Doris; a NetEase-born Apache top-level project since 2022.

Apache License

The Apache License, also known as the Apache Software License, is a permissive open-source license stewarded by the Apache Software Foundation, current as version 2.0 since 2004.

Apache Livy

Apache Livy is an open-source REST service for submitting Spark jobs and managing long-running Spark contexts, originally built by Cloudera, Microsoft, and Hortonworks; an Apache top-level project since May 2026, default port 8998, latest release 0.9.0-incubating.

Apache Lucene

Apache Lucene is a free, open-source search engine library written in Java, created by Doug Cutting in 2000 and now the core of Apache Solr and Elasticsearch.

Apache Maven

Apache Maven is a build automation and project management tool for Java projects, first released in 2004, built around a Project Object Model XML file.

Apache NiFi

Apache NiFi (originally NSA's Niagarafiles) is an Apache open source dataflow system based on flow-based programming, with a web UI, back pressure, site-to-site transfer, and fine-grained data provenance; Top-Level Project since 2015.

Apache Oozie

Apache Oozie: Yahoo!-created workflow scheduler for Hadoop jobs; DAG workflows in hPDL, coordinator and bundle scheduling; Apache Incubator 2011, TLP 2012, retired to the Attic in 2025.

Apache OpenOffice

Apache OpenOffice is a free and open-source productivity suite developed by the Apache Software Foundation. It is a separate project from LibreOffice, which is a fork of OpenOffice.org and is a more actively developed suite.

Apache ORC

Apache ORC (Optimized Row Columnar) is a self-describing, type-aware columnar file format for Hadoop, created in Hive in January 2013, with striped files, three-level indexes, and independent Java and C++ libraries; latest release 2.3.1 (July 2026).

Apache Ozone

Apache Ozone is an open-source distributed object and file store (S3-compatible API, Hadoop ofs:// interface) originating from HDFS-7240, an Apache top-level project since 2020, scaling to billions of objects and exabytes with Raft replication and erasure coding.

Apache Paimon

Apache Paimon (formerly Flink Table Store) is an Apache top-level lake table format combining lake formats with LSM trees for streaming updates, merge engines, deletion vectors, and multimodal AI storage on Flink and Spark lakehouses.

Apache Parquet

Apache Parquet is an open source, column-oriented data file format designed for efficient data storage. It stores values by column, applies per-column encoding, and embeds schema for query engines.

Apache Pig

Apache Pig is an open-source Apache platform for large-data analysis, using the procedural Pig Latin language compiled to MapReduce, Tez, or Spark jobs on Hadoop; developed at Yahoo from 2006, now dormant.

Apache Pinot

Apache Pinot is an open-source distributed OLAP datastore, built at LinkedIn (2013) and now an Apache Top-Level Project, for sub-second user-facing analytics. Distinguished from Druid and ClickHouse by segment-based columnar storage with per-column indexing and high-concurrency streaming ingestion.