Apache Software Foundation Promotes Fluss and Pony Mail to Top-Level Project Status

Overview

The Apache Software Foundation announced on August 6, 2026 that Apache Fluss and Apache Pony Mail have become Top-Level Projects (TLP), graduating both out of the foundation’s Incubator program, according to the ASF.

What We Know

Apache Fluss is described by the foundation as “an open source, lakehouse-native streaming storage system designed for real-time analytics and AI,” which “provides a real-time data layer for lakehouse, bringing streaming data, continuously updated tables, and historical lakehouse data together through a common table abstraction,” according to the ASF. The foundation says Fluss integrates with the Apache Flink and Apache Spark compute engines and with the Apache Paimon, Apache Iceberg, Apache Hudi and Lance lakehouse table formats.

On its own documentation site, Fluss explains the tiered design behind that integration: live data inside a Fluss cluster is kept in a “streaming Arrow format” that “is optimized for low-latency read and write operations,” while data compacted into the lakehouse switches to “Parquet format with higher compression” that “is optimized for efficient analytics and long-term storage,” according to Fluss’s documentation. The project’s GitHub repository, released under the Apache License 2.0, describes Fluss as bridging “data streaming and data warehousing by enabling low-latency, high-throughput ingestion while integrating with Apache Flink and Spark,” according to the Apache Fluss repository.

Feng Wang, head of Open Data Platform at Alibaba Cloud, said the graduation reflects the project’s development history: “Apache Fluss’s graduation reflects a mature community shaped by open, collaborative governance at the ASF. Deployed and proven at scale in Alibaba’s core e-commerce production workloads, Fluss’s Lakestream architecture unifies streams with Lakehouse data, making the Lakehouse real-time while reducing data duplication and pipeline complexity,” according to the ASF.

Apache Pony Mail also graduated the same day. The foundation describes it as “a web-based mail archive browser built to scale to millions of archived messages with hundreds of requests per second” that lets users “browse, search, and interact with mailing lists including creating replies to mailing list threads,” and that “works in both public, private and mixed-mode,” according to the ASF.

Both projects followed the foundation’s standard incubation path, in which the Apache Incubator “hosts incoming projects (called podlings) that want to enter the ASF and adopt The Apache Way” before a graduation vote confers full Top-Level Project status, according to the ASF. The foundation, established in 1999, notes that it also powers projects including “Apache Airflow, Apache Camel, Apache Cassandra, Apache Groovy, Apache HTTP Server, and Apache Kafka,” according to the ASF.

What We Don’t Know

The ASF’s announcement does not disclose when Fluss or Pony Mail first entered the Incubator, how many committers or PMC members either project now has, or the vote tally behind the graduation decision. It also does not provide adoption figures, such as download counts or number of production deployments, beyond noting that Fluss runs inside Alibaba’s own e-commerce infrastructure.

Analysis

Top-Level Project status is largely a governance milestone rather than a technical one: it signals that the ASF’s board considers a project’s community, decision-making process and infrastructure mature enough to operate independently of Incubator mentors, rather than certifying any new feature or performance claim. For Fluss, the promotion arrives as the broader data-infrastructure ecosystem has been consolidating around “lakehouse” architectures that pair streaming ingestion with formats such as Iceberg and Paimon, the same interoperability layer the project’s own documentation and GitHub description both point to.